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

Goes beyond the idempotentHint annotation by stating the concrete observable behavior (returns ok even when the user is not followed) and by disclosing the login/auth requirement, which annotations do not cover. Slight redundancy with idempotentHint=true, but the return-value detail is genuinely additive.

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?

Two short clauses, no filler, action stated first followed by the idempotency caveat. Ideal size for a single-parameter toggle tool.

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 one-parameter mutation with an idempotency annotation and no output schema, the description covers auth, action, and the edge-case return. Only the relationship to follow_creator is left implicit.

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 already documents userId as a cuid. The description adds nothing further about the parameter, so the schema carries the burden and 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 ('取消关注某位主理人'), which is clearly distinct from the sibling follow_creator and from unfollow_product. Precise but does not explicitly name the sibling it pairs with.

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 login prerequisite gives a usable calling condition, and the pairing with follow_creator is implied by the tool name and domain, but there is no explicit when-to-use or when-not-to-use guidance and no named alternative.

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