观看历史

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that results are scoped to the currently authenticated account, which is genuinely useful behavioral context. It says nothing about ordering, pagination beyond the ps cap, or return shape.

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?

One short front-loaded sentence with no redundancy. The parenthetical "（扩展能力）" is the only wasted token and it conveys no actionable information.

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 read-only listing tool with one optional parameter this is close to adequate, but there is no output schema and the description never indicates what a history entry contains or how results are ordered/limited across pages. An agent can call it, but cannot predict the response.

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 description coverage is 100%, with ps fully documented (1-30, default 20, bounds in schema), so the schema does the heavy lifting per the baseline rule. The description adds no additional meaning about what ps controls or whether results are ordered newest-first.

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 (读取观看历史) scoped to the current account, so an agent can tell it apart from write-side siblings like like_video or favorite_video. The trailing "（扩展能力）" is vague filler that adds no distinguishing information, and nearby siblings such as toview (watch-later) are not explicitly contrasted.

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?

There is no statement of when to use this tool versus alternatives; the closest sibling, toview, stores a separate watch-later list and is never mentioned. The agent must infer from the name that this returns already-watched content rather than a saved list.

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