Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is fully covered by structured fields. The description adds value by enumerating the returned fields in the absence of an output schema, but it says nothing about result ordering (relevance vs. score), Stack Overflow API rate limits, or how errors/empty results are surfaced.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The definition is two short sentences and front-loads the resource and return payload before the usage hint, which is efficient. The trailing Example JSON duplicates the input schema's examples array and is the one element that does not earn its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 3-parameter read-only search with no output schema, the description covers purpose, use case and return fields, which is most of what an agent needs. Minor gaps remain around result ordering and rate-limit behaviour, but nothing blocks correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% — each of query, limit (1-10, default 5) and answers (default 1) is already documented in the schema, so the baseline of 3 applies. The inline Example merely restates the schema's own examples object and adds no new semantic meaning about parameter interaction.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific verb (搜索) and a specific resource (Stack Overflow 技术问答), and it lists what comes back (标题、摘要、答案数、得分、链接). This makes it distinguishable from siblings such as github_search or hacker_news_search by resource alone, though the description never explicitly contrasts itself with those alternatives.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

"用于排查代码报错、查技术方案" gives a clear use context that an agent can match against a user's intent. There is no when-not guidance and no mention of when a sibling (e.g. github_search for library-specific issues, web_fetch for blog posts) would be a better pick.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.