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

Annotations already cover readOnly and openWorld, but the description adds real data-fidelity context: search cards may contain only a body snippet, and exact title/publish time must be taken from detail. That is a behavioral trait an agent would otherwise get wrong by trusting the card.

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?

Three compact lines: capability first, then the chaining instructions, then the caveat about card fidelity. Every sentence carries new information and nothing is repeated from the schema.

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 values need no explanation, and the description supplies the two things an agent needs to act: how to chain to the detail/comments tools and that card snippets are not authoritative. Nothing material is missing for a read-only search tool.

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% and the schema already documents sort_type semantics, the 3-day page_token validity, and the keyword constraints, so the schema does the heavy lifting. The description only restates that 综合/最新/最热 sorting and pagination exist, adding no syntax or format detail beyond it — baseline 3.

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 and resource: keyword search over 公众号贴图 (image posts), plus sorting and pagination. It is distinguishable from wechat_search_mp_articles (text articles) and wechat_get_mp_account_image_posts_by_account_id (by account ID) by the keyword/account axis, though it never names those siblings explicitly.

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?

Gives clear downstream usage: feed article_url to wechat_get_mp_article_detail_by_url for body and images, or to wechat_get_mp_article_comments_by_url for comments. It does not state when to prefer this over wechat_search_mp_articles, so the exclusion case is left implicit.

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