Reply To Comment

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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description's one genuine addition beyond structured data is the quota cost ('50 units'), which is useful. It omits any warning that non-idempotent retries can post duplicate replies, and doesn't clarify what 'authorized user' requires.

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?

Two short sentences, zero filler, with the core action front-loaded and the quota note clearly separated. Nothing is padded.

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?

An output schema exists, so return values need no explanation, and the schema fully documents parameters. Still, for a non-idempotent mutation with openWorldHint=true, the description says nothing about permission requirements, threading side effects, or what the quota unit represents, leaving meaningful gaps for an agent deciding whether to call it.

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 all three parameters are documented in the schema, including channel selection and the thread behavior of the comment ID. The description adds nothing beyond that baseline and slightly muddies it by saying 'top-level comment' while the schema allows replying to a reply.

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 ('Reply to a top-level comment') plus the acting identity ('as the authorized user'), so the operation is unambiguous. It does not, however, distinguish itself from nearby siblings like post_comment, edit_comment, or list_replies, leaving the agent to infer the boundary.

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?

There is no explicit when-to-use statement, no comparison to post_comment (which presumably starts a new thread), and no stated preconditions such as owning the comment or having reply permission. The agent must infer the use case 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.