feat(bedrock): forward strict and additionalProperties to Converse toolSpec

[mateo-berri]

Relevant issues

A customer reported that strict: true on tools is silently ignored for Claude on Bedrock: give a tool an enum and ask for a value outside it, and GPT and direct-Anthropic stay inside the enum while Claude-on-Bedrock returns the out-of-enum value. This re-applies the fix from #25209, which was correct and approved (Greptile 5/5) but went stale with merge conflicts since April after unrelated refactors landed in _bedrock_tools_pt. The hunks no longer applied, but the change itself was still valid, so this is a clean rebase onto current staging rather than a rewrite. Related: #10062, #16725, #6136

Linear ticket

Pre-Submission checklist

• I have added meaningful tests
• My PR passes all unit tests on make test-unit
• My PR's scope is as isolated as possible; it only solves 1 specific problem
• I have requested a Greptile review by commenting @greptileai and received a Confidence Score of at least 4/5 before requesting a maintainer review

CI (LiteLLM team)

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Screenshots / Proof of Fix

Reproduce against a live proxy hitting real Bedrock (Claude). Define a tool whose only enum value is celsius and ask for Fahrenheit; before this change the call comes back with additionalProperties/strict dropped and the model free to pick an out-of-enum value, after it the schema reaches Bedrock intact.

curl -s http://localhost:4000/v1/chat/completions \
  -H "Authorization: Bearer $LITELLM_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "bedrock/us.anthropic.claude-sonnet-4-5-20250929-v1:0",
    "messages": [{"role": "user", "content": "What is the weather in Dallas in Fahrenheit? Call the tool."}],
    "tool_choice": "required",
    "tools": [{
      "type": "function",
      "function": {
        "name": "get_weather",
        "strict": true,
        "description": "Get the weather for a city",
        "parameters": {
          "type": "object",
          "properties": {
            "city": {"type": "string"},
            "unit": {"type": "string", "enum": ["celsius"]}
          },
          "required": ["city", "unit"],
          "additionalProperties": false
        }
      }
    }]
  }' | jq '.choices[0].message.tool_calls[0].function.arguments'

With the fix the returned unit stays "celsius" (the only enum member) instead of "fahrenheit".

Type

🐛 Bug Fix

Changes

litellm/types/llms/bedrock.py: add additionalProperties: bool to ToolJsonSchemaBlock and strict: bool to ToolSpecBlock (both total=False, so the keys stay optional).

litellm/litellm_core_utils/prompt_templates/factory.py: in _bedrock_tools_pt, forward strict from the OpenAI function and additionalProperties from the schema, each only when present. Bedrock requires additionalProperties: false alongside strict: true or it rejects the request, so both have to travel together.

tests/llm_translation/test_bedrock_completion.py: add test_bedrock_tools_pt_strict_parameter covering both the pass-through and the absent-by-default cases. It fails (KeyError on strict) without the factory change and passes with it.

[mateo-berri]

Closing in favor of #29814, which carries the identical change on a properly named branch. Continuing review there

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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