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

Goes well beyond the annotations by disclosing the payment model ('Pay per call in stablecoins'), the refund guarantee for undelivered comments, the 100-comment ceiling, and the deliberate omission of commenter names/handles. These are exactly the operational and output-shape facts an agent cannot get from readOnlyHint/idempotentHint.

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?

Front-loads the core action and output fields, then layers limits, omissions, and billing in short clauses. Only the 'for AI agents' framing is mild filler, but nothing is redundant or bloated.

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?

With no output schema, the description carries the return-value burden and does so by naming the exact fields returned and the fields withheld. Combined with the limit and billing/refund disclosure, an agent has everything needed to call and interpret the tool.

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 fully documented, including the coercion rule for out-of-range limit values. The description only restates the 100-comment cap, adding no syntax or format detail beyond the schema; baseline 3 applies.

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?

Names a specific verb and resource ('send the URL of a video and get its comments as JSON') and enumerates the returned fields (text, time, likes, reply count). An agent can distinguish this from the sibling 'tiktok' (video data) and 'youtube-comments' without opening the schema.

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?

Usage is implied by 'send the URL of a video', and the 100-comment cap is stated, but there is no explicit when-to-use guidance and no routing to alternatives such as 'youtube-comments' or the generic 'tiktok' tool. The agent must infer platform selection from the name alone.

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