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

Annotations already declare destructiveHint=true and openWorldHint=false, so the safety profile is partly covered. The description adds real value by making clear that the existing text is replaced (i.e. prior content is lost) and that only the caller's own comments in the given project can be modified. It does not describe the failure mode for a non-owned comment, which keeps it short of a 5.

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, both front-loaded with the action first and the constraint second. Nothing is repeated from the schema and there is no filler.

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 and annotations cover the safety profile, so the description need not explain return values. But for a destructive update with three undocumented, required parameters at 0% coverage, the definition should say whether 'text' replaces the whole comment and what happens on ownership or project mismatch.

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 has to carry the load: it clarifies that projectUid scopes the ownership check and that commentUid identifies the caller's own comment. It adds no format or sourcing details for the UID strings and does not clarify that 'text' is a full replacement rather than a patch, leaving meaningful gaps.

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?

'Replace the text of one of the caller's own comments' gives a specific verb (replace), a specific resource (comment text), and an ownership scope. It is immediately distinguishable from add_comment, delete_comment, and get_comments without opening 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?

The prerequisite 'the comment must belong to projectUid' is stated, which is useful selection context. However, there is no explicit guidance on when to use this instead of add_comment or delete_comment, and the 'own comments only' restriction is stated without saying what to do otherwise. Usage is implied by the tool name rather than spelled out.

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