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

Annotations already disclose the write/open-world/non-idempotent profile. The description adds value beyond them by flagging that authentication is required and that this sends as the user for real (以本人身份实际发文字), justifying the caution to verify content first. It does not describe limits like the 4000-char cap or what happens on failure.

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 compact sentence with the login prerequisite front-loaded. Every clause earns its place, though the punctuation-dense concatenation slightly reduces readability.

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 2-parameter write tool whose annotations already carry the safety profile and no output schema exists, the description covers the auth requirement, the ID source, and the pre-send verification step. Nothing an agent needs to invoke it correctly 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 description coverage is 100%, so the schema already documents both conversationId and content. The description only clarifies where conversationId originates and that content is text; baseline 3 is correct since the schema carries the parameter detail.

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 in 'send text as yourself' (实际发文字) and clarifies it is a real outbound message, not a draft or live-chat post. It does not explicitly name the sibling it contrasts with (e.g., post_live_message or recall_my_message), so it stops short of a 5.

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?

Gives actionable prerequisites: login required, and the conversationId must come from list_my_conversations or start_conversation. The instruction to confirm recipient and full text first ('先确认收件人及全文') is clear context, though it does not state when to prefer alternative message-sending tools.

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