session_list

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

With no annotations, the description carries the full burden. It usefully discloses that only locally saved sessions are returned and that cookie contents are excluded, which signals a safe metadata-only read. However, it does not cover permissions, what happens with no saved sessions, or any behavior beyond the data scope.

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 front-loaded sentence with the resource and returned fields in a parenthetical, plus one scoping exclusion. No wasted text for a simple 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?

An output schema exists, so return values need not be explained further, and the tool has no parameters to document. The description is complete enough for correct invocation; only the absence of explicit sibling routing keeps it from a 5.

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. The description adds the useful note that the output is limited to metadata, but there are no parameters whose semantics need explaining.

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 (列出/list) and resource (本地已保存的登录态), and enumerates the returned fields (session name, host, update time). The explicit '不含 cookie 内容' implicitly separates it from session_export, though neither sibling is named directly.

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?

Usage is implied by the zero-parameter read-only nature of listing sessions, but there is no explicit 'use this when...' or exclusion guidance pointing agents to session_export/import for cookie data. The agent must infer when to prefer this over the export/import siblings.

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