Comment Replies

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

Adds context the annotations do not carry: potential paid credit consumption, the confirm=true gate, and the clarification that these read-like POSTs do not publish to social platforms (resolving the tension with readOnlyHint=false). No detail on rate limits or error behavior, but this is meaningful disclosure beyond the annotation set.

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-loaded with purpose, then token sourcing, pagination, and the credit/confirm caveat. The field enumeration is long but justified because there is no output schema. Slightly dense but every clause earns its place.

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 by listing reply text, author details, like count, and publish date. Combined with the token prerequisite, pagination behavior, and credit/confirm constraints, an agent has everything needed to call this 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 account, confirm, and continuationToken are already documented in the schema. The description restates the token sourcing and pagination semantics without adding new syntax or format detail, so it sits at the baseline.

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?

States a specific verb and resource ('Fetches replies to a specific comment on a YouTube video') and enumerates the returned fields, so it is unambiguous against the sibling youtube_comments (top-level comments) and against the platform-parallel tiktok_comment_replies/instagram_comment_replies.

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?

Gives a concrete prerequisite chain: the required continuationToken must come from the 'repliesContinuationToken' field of the Comments endpoint, or from a prior replies response to paginate further. It does not state when to prefer this over sibling reply tools, but the workflow context is clear.

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