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

readOnlyHint already covers the safety profile, and the description adds real value beyond it: login is required, and ACCEPTED status is explicitly a point-in-time snapshot rather than live state, which warns the agent about staleness. It also enumerates the state fields returned, though it says nothing about failure modes for non-1-1 conversations.

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?

Purpose comes first, followed by state-routing in a compact arrow notation, and every clause carries information. The telegraphic style ('登录;', arrow chains) is dense and slightly cryptic, but nothing is redundant.

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 single-parameter read tool, the description covers what is read, the key state fields, the snapshot caveat, and the next action per state. With no output schema, a brief note on the full shape of the returned status object would close the remaining gap.

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% and conversationId is documented as a 1-1 conversation id, so the schema already carries the parameter meaning. The description's '真人DM' reference is consistent but adds no syntax, format, or validation detail beyond that.

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 names a specific verb+resource: reading real-person DM contact-exchange status along with the returned fields (myContacts/canRequest), which is more concrete than the title alone. It implicitly separates itself from the request/respond siblings by routing to them, though it never states plainly that this tool is read-only for a single 1-1 conversation.

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?

It gives concrete conditional routing: if a request can be made, confirm then use request_contact_exchange; if peerPending, confirm then use respond_contact_exchange; if the user has no contact, use add_profile_link. That is strong guidance for alternatives, but no explicit when-not-to-use case (e.g. group conversations) beyond the schema's 1-1 constraint.

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