get_capabilities

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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: it reports per-source login state and cache/freshness times, and asserts it will not force configuring all accounts at once, i.e. no config side effects.

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 primary content front-loaded and the usage reassurance trailing after a semicolon. Every clause carries information; only the second clause is slightly oblique.

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?

With an output schema present, the description need not enumerate return fields, and strong annotations carry the safety profile. For a zero-parameter status tool the description is adequate, though it could state more explicitly when to prefer this over open_setup or refresh_source.

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 the baseline is 4; there is nothing for the description to disambiguate. Schema coverage is 100% (vacuously) and no parameter semantics are needed.

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 resource set ('可用校园功能', per-source '登录状态', '缓存时间'), so the agent knows this returns a capability/status overview rather than notices, grades, or courses. It does not explicitly name which sibling it supersedes, but the content is distinct enough to separate it from refresh_source and the various get_* tools.

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 clause '不会要求一次配置全部账号' hints at the usage context (safe to inspect without configuring every account, useful before other calls), but there is no explicit 'call this when...' or 'use X instead' routing. Usage is implied rather than stated.

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