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

Annotations only declare idempotentHint and destructiveHint; the description goes much further, adding the login requirement, the fact that the operation is free and repeatable, and concrete failure semantics (403 not_your_need for non-owner, 409 need_closed with the required fallback action). These are exactly the preconditions an agent needs before invoking a state-changing tool.

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: auth, capability, pairing, then the two error branches. Semicolon-compressed phrasing borders on telegraphic and would be harder to parse for a non-Chinese reader, but no sentence is wasted.

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 one-parameter state-changing tool with no output schema, the description covers authentication, ownership scope, repeatability, the two realistic failure modes and the correct alternative to use for each. Nothing an agent needs in order to call 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% with a single needId parameter, so the schema already carries the syntax burden and the baseline of 3 applies. The description does add the important constraint that the id must refer to a need the caller owns, but no format or source details for the id.

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States a specific verb and resource ('恢复本人手动下架需求' – restore your own manually unpublished need) and immediately names its inverse sibling unpublish_need. An agent can tell it apart from create_need, cancel_need and complete_need 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?

Explicitly names the alternative for the excluded case: needs that are cancelled/completed return 409 need_closed and must be re-listed via create_need instead. It also frames the pairing with unpublish_need, so both when-to-use and when-not-to-use are stated.

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