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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, but the description adds substantial context beyond them: a login prerequisite, the irreversible terminal state (no edit/reopen), and the exact error semantics (403 not_your_need, 409 need_already_completed, 409 need_closed). This is genuinely useful behavioral disclosure for an agent deciding whether to call or handle failures.

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?

A single dense sentence, front-loaded with the login requirement and the most decision-relevant fact (terminal state), then the alternative tool, then error codes. Every clause carries information; the semicolon-chaining is compact though slightly crammed.

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 mutation with annotations present and no output schema, the description covers prerequisites, terminal-state behavior, alternative tooling, and failure modes. Little is missing for correct invocation.

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% (needId '需求 id'), so the schema already documents the single parameter. The description adds no syntax or format detail for needId, 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?

States a specific verb+resource (cancel a need) and immediately distinguishes it from siblings: it is a terminal state, unlike the temporary unpublish_need, and implicitly from delete_need/complete_need/reopen_need. An agent can route correctly without opening any other tool.

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 (unpublish_need) and the condition that selects it (temporary takedown), plus states that this action is terminal and cannot be reopened. When-to-use vs. when-not is fully specified.

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