fix(moa): preserve caller tool schemas

[michaelneale]

Summary

• remove natural-language heuristics that narrowed caller-provided tool schemas on MoA actor and continuation turns
• preserve every caller-provided schema unless an explicit forced/allowed subset applies
• retain forced tool_choice behavior as a single-tool subset
• add a multi-turn read_file -> read_file -> write_file regression

Why

MoA's schema relevance classifier recognized write, file_write, and edit_file, but not the common schema name write_file. A read-then-write workflow therefore gave the actor only read_file; after each tool result the recent read chain stayed selected and the reducer genuinely could not call write_file.

Tool availability is an API contract, not something MoA should infer from prompt wording. This deletes that heuristic class rather than adding another alias.

Verification

At commit e8dc0e8d216a543fb22ed856696838e7b5a88ae2:

• cargo test -p mesh-mixture-of-agents (174 unit tests plus complete crate integration/doc suite; 10 network/cost tests remain explicitly ignored)
• cargo clippy -p mesh-mixture-of-agents --all-targets -- -D warnings
• cargo fmt --check
• git diff --check

Summary by CodeRabbit

• Bug Fixes
  • Tool-enabled requests now preserve all caller-provided tools instead of filtering them based on prompt wording.
  • Explicitly permitted tool subsets remain respected.
  • Forced tool selections continue to use only the specified tool.
  • Chained tool interactions now retain the schemas needed for subsequent read and write operations.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 1f5b8029-1683-420f-8f0e-aa867ccbd8a3

📥 Commits

Reviewing files that changed from the base of the PR and between bb88017 and e8dc0e8.

📒 Files selected for processing (3)

• crates/mesh-mixture-of-agents/src/context.rs
• crates/mesh-mixture-of-agents/src/lib.rs
• crates/mesh-mixture-of-agents/src/tool_turn.rs

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📝 Walkthrough

Walkthrough

Tool selection no longer filters tools by prompt text. Query and tool-result paths preserve all caller-provided tools unless allowed_tools restricts them. Tool turns honor forced_tool, and tests verify selection and schema preservation.

Changes

Tool selection behavior

Layer / File(s)	Summary
Selection policy and forced tools crates/mesh-mixture-of-agents/src/lib.rs, crates/mesh-mixture-of-agents/src/tool_turn.rs	Selection helpers now return all session tools or the caller-authorized subset. Forced tool turns select only the forced tool. Obsolete prompt-based selection logic was removed.
Query and reducer integration crates/mesh-mixture-of-agents/src/lib.rs, crates/mesh-mixture-of-agents/src/context.rs	Query and tool-result handling pass the selected tools to context packing. Tests verify preservation of multiple tool schemas and restriction by explicit allowed-tool lists.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Merge Risk: ⚪ Minimal · up to e8dc0

The change preserves caller-provided tool schemas while retaining explicit forced subsets, with regression coverage for the affected multi-turn workflow; no actionable merge-blocking risk remains after normal checks and review.

Sequence Diagram(s)

sequenceDiagram
  participant Caller
  participant QueryHandling
  participant ToolSelection
  participant ReducerContextPacking
  Caller->>QueryHandling: provide tools or allowed_tools
  QueryHandling->>ToolSelection: derive selected tools
  ToolSelection-->>QueryHandling: all tools or allowed subset
  QueryHandling->>ReducerContextPacking: pass selected tool schemas
  ReducerContextPacking-->>Caller: packed context with selected schemas

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Possibly related PRs

• Mesh-LLM/mesh-llm#1000: Modifies MoA tool selection and continuation behavior in lib.rs.
• Mesh-LLM/mesh-llm#1116: Modifies MoA tool selection and tool-turn handling across the same modules.
• Mesh-LLM/mesh-llm#1145: Modifies MoA tool-selection and normalization behavior.

Suggested reviewers: ndizazzo

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: preserving caller-provided tool schemas in MoA.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/moa-preserve-tool-schemas

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