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

Beyond the annotations (readOnlyHint=false, idempotent=false, dry-run not declared there), the description adds real behavioral context: the comment is 'Audited', it is 'Dry run by default', both reviewer and submitter see it, and answering a reviewer's question routes the application back to them — a non-obvious side effect an agent must know. This meaningfully exceeds what the structured fields 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 content is front-loaded: purpose first, then the reviewer/submitter visibility nuance, then the two terse operational flags ('Audited. Dry run by default.'). The parenthetical audience clause is dense but earns its place; nothing is padding.

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 description covers the important operational facts (auditing, dry-run default, visibility, workflow routing). The only remaining gap is that it doesn't explicitly contrast with the near-identical comment_on_application sibling, which an agent choosing between them would benefit from.

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%, so both required parameters (id, text) and dry_run are fully documented in the schema itself, including formats and limits. The description adds only the audience framing around 'id' and repeats the dry-run default, so it does not go meaningfully beyond the schema — baseline 3 applies.

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 — adding a message to a submission — and immediately scopes it by audience ('this key's own account's submissions', or 'any they may see' for a reviewer). That audience split is what separates it from the sibling comment_on_application, so an agent can distinguish the two without opening a 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 gives clear context for when this tool applies (commenting on your own submission, or a reviewer commenting on something visible) and notes the concrete case of answering a reviewer's question. It stops short of naming the alternative sibling (comment_on_application) or stating explicit exclusions, so it is clear-but-not-routing.

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