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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is fully covered structurally. The description contributes the login requirement, which the annotations do not convey, but says nothing about response shape or what the toggle values represent.

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 front-loads the login precondition and then states the resource and read-only nature. No redundant or filler text.

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 zero-parameter read tool with full annotations and no output schema, the description covers purpose, scope, and the auth requirement. It could mention what the returned switch state looks like, but that is a minor gap given the simplicity.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; the schema is empty and fully described. Baseline 4 applies for a no-parameter tool.

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 resource (the upcoming/past public activity display toggle on one's own public homepage) and marks it read-only, which clearly pairs it with update_my_activity_privacy without naming that sibling. An agent can tell what it retrieves, though the 'get' verb is conveyed only through '只读' rather than an explicit verb.

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 '【需要登录】' prefix gives the key prerequisite for use, but there is no explicit when-to-use versus when-to-use-the-alternative guidance. The read-only framing implies this is for inspection only, which is the point at which an agent would switch to update_my_activity_privacy.

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