Reply to a YouTube comment

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

The description goes beyond annotations by explicitly stating 'This is PUBLIC and immediate' and requiring user confirmation ('show the user the exact reply text and get an explicit yes before calling'). This is valuable behavioral context not present in the annotations (which only note readOnly=false, idempotent=false, destructive=false). It also states the channel connection requirement. It could have elaborated on rate limits or error conditions, but given the annotations already cover basic safety, a 4 is appropriate.

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 three sentences with no filler. It front-loads the core action ('Post a public reply'), then immediately highlights the critical warning about publicity and user confirmation, and finally provides the prerequisite and ID sourcing. Every sentence 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?

For a mutation tool with annotations covering the safety profile (readOnly=false, idempotent=false, destructive=false) and no output schema, the description covers everything an agent needs: the action, the public/immediate nature, the confirmation step, how to obtain the ID, and the channel prerequisite. No additional information would materially improve correct invocation.

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 coverage is 100%—both parameters have descriptions ('the reply, shown publicly under the video' and 'id of the comment to reply to (from list_youtube_comments)'). The description adds a minor hint about sourcing commentId from list_youtube_comments, but this only slightly supplements the schema. Per the rubric, a baseline 3 is correct when the schema already fully documents parameters.

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 states a specific verb and resource: 'Post a public reply to a comment on the connected channel, as the channel.' It clearly distinguishes this tool from sibling reply tools (e.g., reply_to_meta_comment, reply_to_reddit_comment) by naming the YouTube context and the connected-channel prerequisite. It also specifies the source of the comment ID, making the action unambiguous.

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?

It provides clear contextual guidance: 'Get commentId from list_youtube_comments' and 'Needs a connected YouTube channel.' It also instructs the agent to obtain explicit user confirmation before calling. It doesn't explicitly state when not to use it versus alternatives, but the platform-specific nature makes that implicit. Minor gap: no mention of alternatives like moderate_youtube_comment, but the use case is distinct.

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