send_private_msg

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

With no annotations, the description carries the full burden. It usefully discloses supported message formats (plain text, CQ code, message-segment array) and the meaning of auto_escape, but says nothing about failure/error behavior, whether the target must already be a friend, rate limits, or what the call returns.

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?

Front-loads the purpose in the first sentence and keeps the format/parameter notes compact and scannable. There is minor redundancy restating parameter descriptions already present in the schema.

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 send tool with no output schema and no annotations, the definition covers formats and escaping but omits return value, error/failure behavior, and any permission or friend-relationship prerequisite, leaving meaningful gaps.

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 the schema already documents all three parameters and the description mostly restates them. It adds a concrete message-segment example that is marginally helpful, but no syntax or format detail beyond the schema baseline.

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 (发送) and resource (私聊消息) with a clear target (指定好友或用户) and names the OneBot 11 action. It is clearly a private-message send, distinguishable in concept from send_group_msg, though it does not explicitly contrast itself with the generic send_msg sibling.

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 usage (private messaging) but gives no explicit when-to-use or when-not guidance, and no routing against alternatives like send_msg, send_private_forward_msg, or send_poke that an agent must choose between.

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