Trim MCP server tool payloads to reduce token consumption

[Copilot]

This PR implements trimmed responses for Azure DevOps MCP server tools to dramatically reduce LLM token consumption while maintaining backward compatibility.

Problem

The MCP server tools were returning full REST API JSON payloads, causing unnecessary token burn and making it difficult for weaker LLMs to extract relevant information. For example:

• ado_resolve_comment was returning 4200+ character responses when a simple "resolved" message would suffice
• ado_list_pull_request_threads was returning verbose payloads with _links objects, deleted comments, and unnecessary author properties

Solution

Added a fullResponse parameter (defaults to false) to key repository tools that provides two response modes:

Trimmed Mode (Default)

• Action tools (resolve_comment, reply_to_comment) return simple success messages
• List tools (list_pull_request_threads, list_pull_request_thread_comments) return filtered data excluding:
  • Deleted comments
  • _links objects
  • Verbose author properties (imageUrl, descriptor, url)

Full Mode (Opt-in)

• Set fullResponse: true to get complete REST API responses for debugging or advanced use cases

Token Savings

Real-world examples show dramatic improvements:

• resolve_comment: 97.3% reduction (1346 → 37 characters)
• reply_to_comment: 92.5% reduction (549 → 41 characters)
• list_pull_request_threads: 55.3% reduction (680 → 304 characters)

Example Usage

// Trimmed response (default)
await server.request({
  method: "tools/call",
  params: {
    name: "repo_resolve_comment",
    arguments: { repositoryId: "repo1", pullRequestId: 123, threadId: 456 }
  }
});
// Returns: "Thread 456 was successfully resolved."

// Full response (opt-in)
await server.request({
  method: "tools/call", 
  params: {
    name: "repo_resolve_comment",
    arguments: { 
      repositoryId: "repo1", 
      pullRequestId: 123, 
      threadId: 456,
      fullResponse: true 
    }
  }
});
// Returns: Complete thread JSON with all properties

Modified Tools

• repo_resolve_comment - Simple success message vs full thread JSON
• repo_reply_to_comment - Simple success message vs full comment JSON
• repo_list_pull_request_threads - Filtered thread data vs complete response
• repo_list_pull_request_thread_comments - Filtered comment data vs complete response

All changes maintain full backward compatibility via the optional fullResponse parameter.

Fixes #36.

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[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None

[Arithmomaniac]

This is a pretty big change to merge straight into main, no? Especially as the default on, but only for certain tools.

[nikolapeja6]

I believe it should be fine - the results of some tools were already being trimmed, this is just a continuation of that.