发送私聊消息

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

Annotations already indicate readOnlyHint=false (mutation), destructiveHint=false, and idempotentHint=false, which signals a non-idempotent write operation. The description adds that the message can be text or an array of message segments, and references send_group_msg for format details. However, it does not disclose potential side effects like rate limits, delivery failure behaviors, or whether sending is asynchronous. Without additional behavioral context, it is adequate but not rich.

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?

The description is a single sentence, front-loaded with the core action ('send a private message to a specified QQ friend'), followed by message format clarification. Every word earns its place; no fluff or repetition. It efficiently communicates the essential purpose and format flexibility.

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 simple single-recipient send tool with a rich schema (two required parameters, high coverage) and no output schema, the description covers the purpose and message format. However, it could mention the auto_escape parameter, which controls plain-text sending and might be essential for certain use cases, but the schema already describes it. There is no mention of sending behavior or failure handling, but with no output schema and sibling context, it is reasonably complete. Slight gap: does not specify that the message can include mentions or other message types, but the reference to send_group_msg covers that.

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?

The schema already provides 100% coverage for all three parameters, including types and descriptions for message and user_id, and a description for auto_escape. The description adds minimal additional meaning: it confirms the message can be a string or array and points to send_group_msg for format specifics. Since schema coverage is high, a baseline of 3 is appropriate.

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?

The description states a specific verb ('send'), resource ('private message to a specified QQ friend'), and content type ('text or OneBot message segments'). It clearly distinguishes itself from sibling send_group_msg by targeting a single user rather than a group. The Chinese title and description are consistent and unambiguous.

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 implies when to use this tool: when sending a private message to an individual, as opposed to send_group_msg which is for group messages. It references send_group_msg for message format details, providing a clear cross-reference. However, it does not explicitly mention when not to use it (e.g., could use generic send_msg) but the sibling context makes the distinction evident.

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