search_timestamp

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

With no annotations, the description must provide behavioral details. It covers authentication methods (cookies_file, env variable, browser cookies) but does not disclose potential errors (e.g., no subtitles found, unsupported video) or output format. This is adequate but not fully comprehensive.

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?

The description is concise, with a clear two-line purpose, followed by structured sections for authentication and parameters. Every sentence adds value without redundancy.

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 tool with 4 parameters, no output schema, and no annotations, the description explains purpose, authentication, and parameters adequately. However, it omits the return format (e.g., timestamp list with context) and error handling, leaving some gaps for an LLM agent.

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%, so the schema already documents parameters. The description's parameter list adds minimal extra value beyond restating purposes. The authentication section provides additional context, but baseline 3 is appropriate.

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 clearly states the tool searches keywords in subtitles and returns timestamp positions, with a usage context of quickly locating topics in a video. This distinguishes it from sibling tools like extract_subtitles (extracts full subtitles) and list_available_subtitles (lists available subtitle tracks).

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 description includes a usage context ('用于快速定位视频中提到某个话题的时间点') but does not explicitly state when not to use this tool or mention alternatives. For example, it could clarify that subtitles must be available first (use list_available_subtitles) or that extract_subtitles is for obtaining full text.

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