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

Annotations only cover idempotentHint and destructiveHint, so the description carries the rest and does add real context: results are public/listed only, each hit carries the author's canOffer, and an empty result is normal rather than evidence of no offline supply. It does not discuss ranking, relevance, or pagination behavior, which keeps it 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?

Extremely dense and front-loaded — purpose first, then the empty-result caveat, then the next-step chain and alternative. The telegraphic semicolon fragments pack a lot in, though the arrow chain and abrupt clauses cost some readability for non-Chinese-oriented agents.

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 two-parameter search tool with no output schema, it covers what is searched, what is returned (canOffer), how to interpret an empty response, and what to call next or instead. Nothing an agent needs in order to invoke it 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 coverage is 100% (q described as natural language or keyword, limit as count with default 20), so the schema already does the parameter work. The description's '关键词+向量' hints at the hybrid retrieval mechanism behind q, but adds no format or constraint detail beyond that, matching the 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: hybrid keyword + vector search over public, currently-listed needs, and notes results include the author's canOffer. It explicitly contrasts with list_my_needs, so an agent can distinguish it from the sibling that returns the caller's own needs.

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 the follow-on flow (get_need → contact_need → send_message) and an explicit alternative for the caller's own needs (list_my_needs). It does not, however, distinguish this from other discovery siblings such as list_needs_feed, search_all, or find_customer_needs, so the boundary there is left to inference.

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