发送私信

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

Annotations declare destructiveHint=true and idempotentHint=false, and the description adds the crucial non-obvious behavior that the call is a dry-run unless confirm=true, plus that delivery is immediate. It does not cover retraction, rate limits, or duplicate-send behavior, but it goes meaningfully beyond the annotations.

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 short sentences, front-loaded with the action, then the preview/send rule, then the delivery consequence. No filler or repetition.

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 mutation tool with no output schema, the definition covers the action, the safety gate, and the delivery effect, which is what an agent needs to call it correctly. Minor gaps remain around failure modes and rate limits, but nothing essential 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%, so receiver_id, text, and confirm are already documented in the schema. The description restates the confirm-to-send semantics and adds nothing about formats or constraints beyond the schema, so 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 and resource ('给指定用户发送私信') plus the recipient scope, which cleanly separates it from read-side siblings like messages and from content-posting siblings like post_comment or post_dynamic.

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 defines the operating mode: default is preview only, and confirm=true is required to actually send. That is clear when-to-use guidance for the send path, though it never names an alternative tool or says when not to message a user.

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