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

Annotations only declare readOnlyHint/openWorldHint; the description adds real behavioral context — result scope excludes forums/users/topics/suggestions, ordering is preserved, and media fields come only from search results and may be incomplete (so media counts cannot be trusted). No mention of auth, rate limits, or failure modes beyond the empty-page case, so it stops just short of 5.

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?

Four short sentences, each carrying a distinct fact (purpose, exclusions/routing, pagination edge case, media caveat). The core purpose is front-loaded in the first sentence and nothing is redundant.

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?

An output schema exists so return fields need no explanation, yet the description still covers the higher-value gaps: which result categories are absent, how pagination terminates, and the unreliability of media data. An agent has everything needed to call it and interpret the response.

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 coverage is 100%, so both keyword and page_token are already documented with examples and constraints. The description reinforces the page_token continuation semantics but adds no syntax or format detail beyond the schema, so baseline 3 is appropriate.

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?

States a specific verb+resource+scope: "按关键词获取百度贴吧综合搜索中的帖子" with the explicit qualifiers that order is preserved and pagination is supported. It also names what it does NOT cover (吧、用户、话题、搜索建议), which lets an agent separate it from the other search siblings without opening the schema.

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?

Routes the agent explicitly: use 帖子搜索 when latest/earliest/relevant sorting is needed, and use the detail tool when a post link or ID is given. It also states the pagination continuation rule (empty page still judged by next_page_token), which is exactly the when-to-use guidance an agent needs.

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