youtube_get_video_info

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds the specific metadata fields returned, which is useful context beyond annotations. However, it does not disclose any limitations, error conditions, or response format, which is acceptable given annotation coverage but not exceptional.

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 a single, well-structured sentence that lists the key metadata fields. It is front-loaded and every word adds value, with no redundancy or irrelevant 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 one-parameter read-only tool with no output schema, the description adequately conveys the purpose and return content by listing metadata fields. It does not mention caveats like video availability or authentication, but given the simplicity and annotations, it is sufficiently complete.

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 schema fully describes the only parameter 'url' as 'YouTube video URL or ID' (100% coverage). The description adds no additional meaning about the parameter, so it relies entirely on the schema. 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 provides detailed metadata for a YouTube video, listing specific fields (title, duration, views, channel, description, tags). This distinguishes it from sibling tools like channel info or search. However, it lacks an explicit verb like 'retrieves' or 'returns', so it's not a perfect 5.

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 implies the tool is for fetching metadata of a specific video, but it does not explicitly state when to use it over alternatives like youtube_get_channel_info or youtube_search. No exclusions or comparison to siblings are provided, so only implied usage is present.

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