Reply to comment

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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the write-but-safe profile is covered; the description's added value is the non-obvious fact that posting a reply does not change the comment's resolved state. It says nothing about permissions, whether the reply triggers notifications, or whether the created reply is returned (no output schema exists), leaving real behavioral blanks for a mutation tool.

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 sentences, no filler, and the critical non-resolution constraint is front-loaded in caps before the usage guidance. 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?

For a simple three-required-parameter write with full schema coverage, the description covers purpose, the key state-caveat, and when to choose it. Only the return behavior and any permission requirements are unaddressed, which is a minor omission at this complexity level.

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% with all three required parameters documented, so the schema already carries parameter meaning; the description adds no format or constraint detail (e.g., reply length, whether text supports markdown). Baseline 3 is appropriate.

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?

"Add a reply to a comment WITHOUT resolving it" gives a specific verb (add reply), the resource (comment), and an explicit scope boundary (no resolution) that separates it from resolve_comment in the sibling list. An agent can distinguish it without reading any 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?

It states concretely when to use it (comment is a question, needs discussion, or a response before deciding) and gives a condition for the alternative behavior ("resolve only once the issue is actually addressed"). The alternative is described behaviorally but the sibling tool name resolve_comment is never cited explicitly, which is the only gap.

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