diff --git a/.github/workflows/gh-aw-estc-pr-buildkite-detective.lock.yml b/.github/workflows/gh-aw-estc-pr-buildkite-detective.lock.yml
index 20eb7ef7..a572738f 100644
--- a/.github/workflows/gh-aw-estc-pr-buildkite-detective.lock.yml
+++ b/.github/workflows/gh-aw-estc-pr-buildkite-detective.lock.yml
@@ -36,7 +36,7 @@
 #
 # inlined-imports: true
 #
-# gh-aw-metadata: {"schema_version":"v2","frontmatter_hash":"df8ca7d584d83760b992c10ddce0dd529cb00c17400cf20aff40103ae7002b6e"}
+# gh-aw-metadata: {"schema_version":"v2","frontmatter_hash":"3882c6673727a6d21ba110797bf529eb51a5dd30d5804598ae6495a118485d5f"}
 
 name: "PR Buildkite Detective"
 "on":
@@ -171,13 +171,6 @@ jobs:
         env:
           GH_AW_PROMPT: /tmp/gh-aw/aw-prompts/prompt.txt
           GH_AW_SAFE_OUTPUTS: ${{ env.GH_AW_SAFE_OUTPUTS }}
-          GH_AW_ENV_BK_BRANCHES: ${{ env.BK_BRANCHES }}
-          GH_AW_ENV_BK_COMMIT_SHA: ${{ env.BK_COMMIT_SHA }}
-          GH_AW_ENV_BK_EVENT_ID: ${{ env.BK_EVENT_ID }}
-          GH_AW_ENV_BK_EVENT_NAME: ${{ env.BK_EVENT_NAME }}
-          GH_AW_ENV_BK_FAILURE_STATE: ${{ env.BK_FAILURE_STATE }}
-          GH_AW_ENV_BK_PR_NUMBERS: ${{ env.BK_PR_NUMBERS }}
-          GH_AW_ENV_BK_TARGET_URL: ${{ env.BK_TARGET_URL }}
           GH_AW_EXPR_0EAAB79A: ${{ inputs.buildkite-pipeline }}
           GH_AW_EXPR_49B959F1: ${{ inputs.additional-instructions }}
           GH_AW_EXPR_6908A9DD: ${{ inputs.buildkite-org }}
@@ -329,15 +322,10 @@ jobs:
           ## Context
           
           - **Repository**: __GH_AW_GITHUB_REPOSITORY__
-          - **Event Name**: __GH_AW_ENV_BK_EVENT_NAME__
-          - **Event ID**: __GH_AW_ENV_BK_EVENT_ID__
-          - **Failure State**: __GH_AW_ENV_BK_FAILURE_STATE__
-          - **Commit SHA**: __GH_AW_ENV_BK_COMMIT_SHA__
-          - **Target URL**: __GH_AW_ENV_BK_TARGET_URL__
-          - **PR Numbers**: __GH_AW_ENV_BK_PR_NUMBERS__
-          - **Branches**: __GH_AW_ENV_BK_BRANCHES__
           - **Buildkite Organization**: __GH_AW_EXPR_6908A9DD__
           
+          **Read `/tmp/gh-aw/buildkite-event.txt` first.** It contains the event context (commit SHA, target URL, PR numbers, branches, failure state) extracted from the GitHub event payload.
+          
           ## Constraints
           
           - **CAN**: Read files, search code, run tests and commands, query Buildkite via MCP, comment on PRs
@@ -366,10 +354,10 @@ jobs:
           
           ### Step 1: Gather Context
           
-          1. Use the commit SHA provided in the Context section above. If it is empty, discover it from the PR's commit statuses or check runs.
+          1. Read `/tmp/gh-aw/buildkite-event.txt` to get the event context. Use the `commit_sha` value. If it is empty, discover it from the PR's commit statuses or check runs.
           2. Find the associated pull request(s):
-             - If **PR Numbers** in the Context section above is non-empty (e.g., from `check_run` events), use those PR numbers directly with `pull_request_read` method `get`.
-             - Otherwise, use `bash` + `gh api repos/__GH_AW_GITHUB_REPOSITORY__/commits/{commit_sha}/pulls` to find PRs containing the commit SHA. Filter the results to keep only PRs whose `state` is `"open"` and, when **Branches** is available, whose `head.ref` matches one of the listed branches. If no candidates remain, also try searching open PRs whose head branch matches one of the **Branches** listed in the Context section.
+             - If `pr_numbers` is non-empty (from `check_run` events), use those PR numbers directly with `pull_request_read` method `get`.
+             - Otherwise, use `bash` + `gh api repos/__GH_AW_GITHUB_REPOSITORY__/commits/{commit_sha}/pulls` to find PRs containing the commit SHA. Filter the results to keep only PRs whose `state` is `"open"` and, when `branches` is non-empty, whose `head.ref` matches one of the listed branches. If no candidates remain, also try searching open PRs whose head branch matches one of the branches.
              - If no PR is found after all attempts, call `noop` with message "No pull request associated with failed commit status; nothing to do" and stop.
           3. For each matching PR, call `pull_request_read` with method `get` to capture the author, branches, and fork status for downstream analysis.
           
@@ -440,13 +428,6 @@ jobs:
         uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
         env:
           GH_AW_PROMPT: /tmp/gh-aw/aw-prompts/prompt.txt
-          GH_AW_ENV_BK_BRANCHES: ${{ env.BK_BRANCHES }}
-          GH_AW_ENV_BK_COMMIT_SHA: ${{ env.BK_COMMIT_SHA }}
-          GH_AW_ENV_BK_EVENT_ID: ${{ env.BK_EVENT_ID }}
-          GH_AW_ENV_BK_EVENT_NAME: ${{ env.BK_EVENT_NAME }}
-          GH_AW_ENV_BK_FAILURE_STATE: ${{ env.BK_FAILURE_STATE }}
-          GH_AW_ENV_BK_PR_NUMBERS: ${{ env.BK_PR_NUMBERS }}
-          GH_AW_ENV_BK_TARGET_URL: ${{ env.BK_TARGET_URL }}
           GH_AW_GITHUB_REPOSITORY: ${{ github.repository }}
           GH_AW_EXPR_49B959F1: ${{ inputs.additional-instructions }}
           GH_AW_EXPR_6908A9DD: ${{ inputs.buildkite-org }}
@@ -461,13 +442,6 @@ jobs:
         uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
         env:
           GH_AW_PROMPT: /tmp/gh-aw/aw-prompts/prompt.txt
-          GH_AW_ENV_BK_BRANCHES: ${{ env.BK_BRANCHES }}
-          GH_AW_ENV_BK_COMMIT_SHA: ${{ env.BK_COMMIT_SHA }}
-          GH_AW_ENV_BK_EVENT_ID: ${{ env.BK_EVENT_ID }}
-          GH_AW_ENV_BK_EVENT_NAME: ${{ env.BK_EVENT_NAME }}
-          GH_AW_ENV_BK_FAILURE_STATE: ${{ env.BK_FAILURE_STATE }}
-          GH_AW_ENV_BK_PR_NUMBERS: ${{ env.BK_PR_NUMBERS }}
-          GH_AW_ENV_BK_TARGET_URL: ${{ env.BK_TARGET_URL }}
           GH_AW_EXPR_0EAAB79A: ${{ inputs.buildkite-pipeline }}
           GH_AW_EXPR_49B959F1: ${{ inputs.additional-instructions }}
           GH_AW_EXPR_6908A9DD: ${{ inputs.buildkite-org }}
@@ -491,13 +465,6 @@ jobs:
             return await substitutePlaceholders({
               file: process.env.GH_AW_PROMPT,
               substitutions: {
-                GH_AW_ENV_BK_BRANCHES: process.env.GH_AW_ENV_BK_BRANCHES,
-                GH_AW_ENV_BK_COMMIT_SHA: process.env.GH_AW_ENV_BK_COMMIT_SHA,
-                GH_AW_ENV_BK_EVENT_ID: process.env.GH_AW_ENV_BK_EVENT_ID,
-                GH_AW_ENV_BK_EVENT_NAME: process.env.GH_AW_ENV_BK_EVENT_NAME,
-                GH_AW_ENV_BK_FAILURE_STATE: process.env.GH_AW_ENV_BK_FAILURE_STATE,
-                GH_AW_ENV_BK_PR_NUMBERS: process.env.GH_AW_ENV_BK_PR_NUMBERS,
-                GH_AW_ENV_BK_TARGET_URL: process.env.GH_AW_ENV_BK_TARGET_URL,
                 GH_AW_EXPR_0EAAB79A: process.env.GH_AW_EXPR_0EAAB79A,
                 GH_AW_EXPR_49B959F1: process.env.GH_AW_EXPR_49B959F1,
                 GH_AW_EXPR_6908A9DD: process.env.GH_AW_EXPR_6908A9DD,
@@ -623,24 +590,7 @@ jobs:
         run: "set -euo pipefail\nif [ -f \"AGENTS.md\" ]; then\n  cp AGENTS.md /tmp/agents.md\n  echo \"Repository conventions copied from AGENTS.md to /tmp/agents.md\"\nelse\n  OWNER=\"${GITHUB_REPOSITORY%/*}\"\n  REPO=\"${GITHUB_REPOSITORY#*/}\"\n  summary=$(curl -sf --max-time 15 -X POST https://agents-md-generator.fastmcp.app/mcp \\\n    -H \"Content-Type: application/json\" \\\n    -H \"Accept: application/json, text/event-stream\" \\\n    -d \"{\\\"jsonrpc\\\":\\\"2.0\\\",\\\"id\\\":1,\\\"method\\\":\\\"tools/call\\\",\\\"params\\\":{\\\"name\\\":\\\"generate_agents_md\\\",\\\"arguments\\\":{\\\"owner\\\":\\\"${OWNER}\\\",\\\"repo\\\":\\\"${REPO}\\\"}}}\" \\\n    | sed 's/^data: //' \\\n    | jq -r '.result.structuredContent.summary // empty' 2>/dev/null) || true\n  if [ -n \"$summary\" ]; then\n    echo \"$summary\" > /tmp/agents.md\n    echo \"Repository conventions written to /tmp/agents.md\"\n  else\n    echo \"::warning::Could not fetch repository conventions; continuing without them\"\n  fi\nfi"
         shell: bash
       - name: Resolve event context
-        run: |
-          set -euo pipefail
-          echo "BK_EVENT_NAME=$GITHUB_EVENT_NAME" >> "$GITHUB_ENV"
-          if [ "$GITHUB_EVENT_NAME" = "status" ]; then
-            echo "BK_EVENT_ID=$(jq -r '.id' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-            echo "BK_FAILURE_STATE=$(jq -r '.state' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-            echo "BK_COMMIT_SHA=$(jq -r '.commit.sha' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-            echo "BK_TARGET_URL=$(jq -r '.target_url // empty' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-            echo "BK_BRANCHES=$(jq -c '[(.branches // [])[].name]' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-            echo "BK_PR_NUMBERS=" >> "$GITHUB_ENV"
-          else
-            echo "BK_EVENT_ID=$(jq -r '.check_run.id' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-            echo "BK_FAILURE_STATE=$(jq -r '.check_run.conclusion' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-            echo "BK_COMMIT_SHA=$(jq -r '.check_run.head_sha' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-            echo "BK_TARGET_URL=$(jq -r '.check_run.details_url // empty' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-            echo "BK_BRANCHES=" >> "$GITHUB_ENV"
-            echo "BK_PR_NUMBERS=$(jq -rc '[(.check_run.pull_requests // [])[].number] | if length == 0 then "" else . end' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-          fi
+        run: "set -euo pipefail\nmkdir -p /tmp/gh-aw\n{\n  echo \"event_name: $GITHUB_EVENT_NAME\"\n  if [ \"$GITHUB_EVENT_NAME\" = \"status\" ]; then\n    echo \"event_id: $(jq -r '.id' \"$GITHUB_EVENT_PATH\")\"\n    echo \"failure_state: $(jq -r '.state' \"$GITHUB_EVENT_PATH\")\"\n    echo \"commit_sha: $(jq -r '.commit.sha' \"$GITHUB_EVENT_PATH\")\"\n    echo \"target_url: $(jq -r '.target_url // empty' \"$GITHUB_EVENT_PATH\")\"\n    echo \"branches: $(jq -r '[(.branches // [])[].name] | join(\", \")' \"$GITHUB_EVENT_PATH\")\"\n    echo \"pr_numbers:\"\n  else\n    echo \"event_id: $(jq -r '.check_run.id' \"$GITHUB_EVENT_PATH\")\"\n    echo \"failure_state: $(jq -r '.check_run.conclusion' \"$GITHUB_EVENT_PATH\")\"\n    echo \"commit_sha: $(jq -r '.check_run.head_sha' \"$GITHUB_EVENT_PATH\")\"\n    echo \"target_url: $(jq -r '.check_run.details_url // empty' \"$GITHUB_EVENT_PATH\")\"\n    echo \"branches:\"\n    echo \"pr_numbers: $(jq -r '[(.check_run.pull_requests // [])[].number | tostring] | join(\", \")' \"$GITHUB_EVENT_PATH\")\"\n  fi\n} > /tmp/gh-aw/buildkite-event.txt\necho \"Buildkite event context:\"\ncat /tmp/gh-aw/buildkite-event.txt\n"
       - env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/gh-aw-estc-pr-buildkite-detective.md b/.github/workflows/gh-aw-estc-pr-buildkite-detective.md
index 4e71c113..f5b7f97c 100644
--- a/.github/workflows/gh-aw-estc-pr-buildkite-detective.md
+++ b/.github/workflows/gh-aw-estc-pr-buildkite-detective.md
@@ -96,22 +96,27 @@ steps:
   - name: Resolve event context
     run: |
       set -euo pipefail
-      echo "BK_EVENT_NAME=$GITHUB_EVENT_NAME" >> "$GITHUB_ENV"
-      if [ "$GITHUB_EVENT_NAME" = "status" ]; then
-        echo "BK_EVENT_ID=$(jq -r '.id' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-        echo "BK_FAILURE_STATE=$(jq -r '.state' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-        echo "BK_COMMIT_SHA=$(jq -r '.commit.sha' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-        echo "BK_TARGET_URL=$(jq -r '.target_url // empty' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-        echo "BK_BRANCHES=$(jq -c '[(.branches // [])[].name]' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-        echo "BK_PR_NUMBERS=" >> "$GITHUB_ENV"
-      else
-        echo "BK_EVENT_ID=$(jq -r '.check_run.id' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-        echo "BK_FAILURE_STATE=$(jq -r '.check_run.conclusion' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-        echo "BK_COMMIT_SHA=$(jq -r '.check_run.head_sha' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-        echo "BK_TARGET_URL=$(jq -r '.check_run.details_url // empty' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-        echo "BK_BRANCHES=" >> "$GITHUB_ENV"
-        echo "BK_PR_NUMBERS=$(jq -rc '[(.check_run.pull_requests // [])[].number] | if length == 0 then "" else . end' "$GITHUB_EVENT_PATH")" >> "$GITHUB_ENV"
-      fi
+      mkdir -p /tmp/gh-aw
+      {
+        echo "event_name: $GITHUB_EVENT_NAME"
+        if [ "$GITHUB_EVENT_NAME" = "status" ]; then
+          echo "event_id: $(jq -r '.id' "$GITHUB_EVENT_PATH")"
+          echo "failure_state: $(jq -r '.state' "$GITHUB_EVENT_PATH")"
+          echo "commit_sha: $(jq -r '.commit.sha' "$GITHUB_EVENT_PATH")"
+          echo "target_url: $(jq -r '.target_url // empty' "$GITHUB_EVENT_PATH")"
+          echo "branches: $(jq -r '[(.branches // [])[].name] | join(", ")' "$GITHUB_EVENT_PATH")"
+          echo "pr_numbers:"
+        else
+          echo "event_id: $(jq -r '.check_run.id' "$GITHUB_EVENT_PATH")"
+          echo "failure_state: $(jq -r '.check_run.conclusion' "$GITHUB_EVENT_PATH")"
+          echo "commit_sha: $(jq -r '.check_run.head_sha' "$GITHUB_EVENT_PATH")"
+          echo "target_url: $(jq -r '.check_run.details_url // empty' "$GITHUB_EVENT_PATH")"
+          echo "branches:"
+          echo "pr_numbers: $(jq -r '[(.check_run.pull_requests // [])[].number | tostring] | join(", ")' "$GITHUB_EVENT_PATH")"
+        fi
+      } > /tmp/gh-aw/buildkite-event.txt
+      echo "Buildkite event context:"
+      cat /tmp/gh-aw/buildkite-event.txt
   - name: Repo-specific setup
     if: ${{ inputs.setup-commands != '' }}
     env:
@@ -128,15 +133,10 @@ Analyze failed Buildkite CI builds for pull requests in ${{ github.repository }}
 ## Context
 
 - **Repository**: ${{ github.repository }}
-- **Event Name**: ${{ env.BK_EVENT_NAME }}
-- **Event ID**: ${{ env.BK_EVENT_ID }}
-- **Failure State**: ${{ env.BK_FAILURE_STATE }}
-- **Commit SHA**: ${{ env.BK_COMMIT_SHA }}
-- **Target URL**: ${{ env.BK_TARGET_URL }}
-- **PR Numbers**: ${{ env.BK_PR_NUMBERS }}
-- **Branches**: ${{ env.BK_BRANCHES }}
 - **Buildkite Organization**: ${{ inputs.buildkite-org }}
 
+**Read `/tmp/gh-aw/buildkite-event.txt` first.** It contains the event context (commit SHA, target URL, PR numbers, branches, failure state) extracted from the GitHub event payload.
+
 ## Constraints
 
 - **CAN**: Read files, search code, run tests and commands, query Buildkite via MCP, comment on PRs
@@ -165,10 +165,10 @@ Classify each failure to guide your investigation:
 
 ### Step 1: Gather Context
 
-1. Use the commit SHA provided in the Context section above. If it is empty, discover it from the PR's commit statuses or check runs.
+1. Read `/tmp/gh-aw/buildkite-event.txt` to get the event context. Use the `commit_sha` value. If it is empty, discover it from the PR's commit statuses or check runs.
 2. Find the associated pull request(s):
-   - If **PR Numbers** in the Context section above is non-empty (e.g., from `check_run` events), use those PR numbers directly with `pull_request_read` method `get`.
-   - Otherwise, use `bash` + `gh api repos/${{ github.repository }}/commits/{commit_sha}/pulls` to find PRs containing the commit SHA. Filter the results to keep only PRs whose `state` is `"open"` and, when **Branches** is available, whose `head.ref` matches one of the listed branches. If no candidates remain, also try searching open PRs whose head branch matches one of the **Branches** listed in the Context section.
+   - If `pr_numbers` is non-empty (from `check_run` events), use those PR numbers directly with `pull_request_read` method `get`.
+   - Otherwise, use `bash` + `gh api repos/${{ github.repository }}/commits/{commit_sha}/pulls` to find PRs containing the commit SHA. Filter the results to keep only PRs whose `state` is `"open"` and, when `branches` is non-empty, whose `head.ref` matches one of the listed branches. If no candidates remain, also try searching open PRs whose head branch matches one of the branches.
    - If no PR is found after all attempts, call `noop` with message "No pull request associated with failed commit status; nothing to do" and stop.
 3. For each matching PR, call `pull_request_read` with method `get` to capture the author, branches, and fork status for downstream analysis.