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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds real behavioral context beyond that: it discloses pagination via page_token and that the returned user_id is the handoff key for the profile and posted-videos tools, which helps chain calls. It does not mention rate limits or quota costs, so it stops short of a 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?

The content is front-loaded with the primary purpose and the routing guidance is compactly appended with no filler sentences. It is slightly dense with three distinct ideas (search scope, pagination, downstream tooling) in one block, but every clause earns 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?

With an output schema present, return-value documentation is not needed, and the description still covers the essentials: search scope, the pagination parameter's role, what the returned user_id is for, and which sibling to use when the ID is already known. Nothing an agent needs to call this correctly is missing.

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%, so both keyword and page_token are already documented in the schema (including the 'leave empty first time, reuse next_page_token with unchanged keyword' rule). The description's mention of page_token pagination adds framing but no syntax or constraints beyond the schema, so the baseline 3 applies.

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 states a specific verb and resource (查找微信视频号用户) plus the two supported lookup modes (keyword or 视频号 ID), which immediately separates it from siblings like wechat_search_videos and wechat_search_mp_articles. It also states what is out of scope (微信联系人和公众号), so an agent can disambiguate without opening any 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?

It explicitly routes the agent: when a user_id or 作品链接 is already available, use the user-profile tool instead of this search, and it explicitly excludes contact and official-account search. That is a clear when-to-use, when-not-to-use, and named-alternative statement.

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