reply_to_comment

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

Annotations only tell the agent this is a non-read-only, non-destructive, non-idempotent open-world call; the description goes much further by disclosing the preview/execute two-step, that text is posted verbatim and publicly, and the concrete failure limits (hidden comments, live videos, replies always attaching to the top-level comment). That is exactly the context the boolean hints cannot convey.

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 critical instruction (confirm=false first) is front-loaded and the labeled Args/Limits sections make it scannable. Minor redundancy: the Returns line restates what the output schema already documents, and the Args block repeats parameter names before adding value.

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 mutating, publicly-visible, open-world tool with an output schema, everything an agent needs is present: input sourcing, the safety workflow, success shape, and hard failure conditions. No material gap remains.

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 0%, so the description carries the full burden, and it does: comment_id's source, message's verbatim/public semantics, and confirm's false=preview default versus true=post. Each parameter gains meaning that the bare schema titles do not provide.

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 ("Post a public reply to a comment") plus the acting identity ("as the user's account"), which separates it cleanly from the sibling hide_comment and delete_comment tools that operate on the same resource. No schema inspection is needed to know what this does.

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?

"Use when the user wants to answer a comment" gives the trigger, "Get comment_id from get_media_comments" names the prerequisite sibling, and the ALWAYS-confirm=false-first rule spells out the exact two-call workflow with the approval gate. When/when-not and the alternative source of input are both explicit.

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