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

No annotations are provided, so the description carries the burden. It mentions billing per call (1 credit) and indicates pagination via nextToken, but does not disclose any side effects, authentication requirements, or error scenarios. This is typical for a read operation, but not fully transparent.

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 (two sentences plus group/billing metadata) and front-loads the core purpose. It contains no fluff or redundancy, making it efficient for an agent to parse.

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 schema and description, an agent has enough context to invoke the tool correctly. It covers inputs, sorting, pagination, and cost. It does not describe output structure, but that is not required since no output schema exists. The only minor gap is explicit guidance on when to prefer this over video comments, but it is inferable.

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 already provides descriptions for all 5 parameters with 100% coverage. The description adds minimal new information—only reinforcing sorting and pagination. Since schema coverage is full, the baseline is 3, and the description does not significantly enhance parameter understanding.

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 primary function: 'Retrieves comments for a YouTube post' with sorting and pagination. This distinguishes it from sibling tools that handle video comments or other post-related actions.

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 mentions sorting and pagination capabilities, but does not explicitly compare alternatives like video comments. However, the name and context make the intended use obvious enough for an agent to select it when post comments are needed.

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