Hosted search_issues silently returns incorrect keyword results

首先，针对托管的 MCP 端点复现列出的 search_issues 查询，并将其与 GitHub REST GET /search/issues 进行比较。然后跟踪 search_issues 的实现和托管请求路径；当关键词查询保留 GitHub 搜索语义，或返回明确的不支持查询/错误信号，而不是静默返回错误的成功结果时，即视为完成。

Bug description

The hosted GitHub MCP search_issues tool silently returns materially incorrect keyword search results while reporting incomplete_results: false.

This reproduces when calling the hosted endpoint directly, without an MCP aggregator.

Environment

• Endpoint: https://api.githubcopilot.com/mcp
• Server: github-mcp-server
• Reported version: github-mcp-server/remote-34ac9c16f8fd3e2a5af74929de89de3a11e98f9b
• Protocol negotiated: 2025-11-25
• Date verified: 2026-08-31

Reproduction

Call search_issues with ordinary GitHub issue search syntax already scoped to issues.

The three returned hooks results were titled plugins, trap, and Hook before Exit, which also does not match normal GitHub full-text search behavior.

Passing owner and repo separately with a keyword-only query produced the same incorrect results, so this is not limited to embedding repo: in query.

Qualifier-only searches such as repo:modelcontextprotocol/python-sdk label:bug return plausible counts, which makes the keyword failure easy for an agent to trust silently.

Expected behavior

search_issues should preserve GitHub issue search semantics and return counts/results consistent with the GitHub REST Search API for the same effective query, or return an explicit error/unsupported-query signal.

Actual behavior

The tool returns a successful response with incomplete_results: false, but keyword matches are missing or unrelated.

Impact

Agents can incorrectly conclude that an issue, bug report, or prior discussion does not exist. This is a correctness failure rather than only a ranking-quality difference.