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

Annotations mark this as a non-read-only, non-destructive, closed-world write, but they say nothing about side effects. The description adds two genuinely useful behavioral facts: repeat likes are idempotent ("已经点过不会报错") and liking an expired post renews it for 24 hours, a mutation the agent could not learn from structured fields. Auth requirements and return behavior are still unstated.

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?

Four short sentences, each carrying distinct information: action, input sourcing, idempotency, and expiry side effect. Nothing is repeated from the schema and nothing is padding.

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 write tool with no output schema, the description covers what to pass, where to get it, and the two non-obvious behaviors. What remains missing is authorization context and a note on what the call returns, which are minor for this complexity level.

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 already 100%, so the schema documents the single post_id including accepted formats. The description still contributes meaning by naming the three sibling tools whose results can supply the id, which the schema does not say. This is a modest but real addition beyond 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?

"给某条帖子点赞" states a specific verb (like) and resource (post), which an agent can act on immediately. It does not mention the sibling unlike_post, so the agent must infer that toggling off is a separate tool rather than a parameter here.

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?

The description gives practical preconditions: post_id must come from search_posts, get_post_detail, or find_nearby, which tells the agent how to obtain the input before calling. It omits any statement about when to prefer unlike_post or any permission prerequisites.

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