youtube_get_comments

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

Annotations already provide readOnlyHint and destructiveHint, and the description adds meaningful context: requires YOUTUBE_API_KEY, returns structured comment records, and enumerates failure scenarios (comments disabled, video unavailable, quota exhausted). This goes well beyond annotations and helps the agent anticipate errors.

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?

Three sentences, each earning its place: purpose, use case, and behavioral notes. Information is front-loaded and there is no redundancy or fluff.

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?

Given the tool's simplicity (2 params, read-only, no output schema), the description covers purpose, usage boundaries, auth requirements, return type, and failure modes. It is fully sufficient for an agent to select and invoke the tool correctly.

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 both parameters are already documented. The description mentions max_results but adds no new semantics beyond what the schema states. Baseline 3 applies because structured data carries the burden.

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 retrieves top-level comments for a YouTube video, using the specific verb "Retrieve" and resource. It distinguishes from siblings by explicitly saying "not video metadata or transcripts," making it unique among the tool list.

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 gives clear context: "Use this for audience reactions," and excludes metadata/transcripts. It does not name alternative tools directly, but the sibling list and exclusions imply the boundaries. This is strong but lacks a named alternative, so not a 5.

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