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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds only that it shares an engine with the PR-description tool; it says nothing about accepted diff format, output shape, determinism, or whether the result is a raw string.

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 with the core purpose front-loaded and no filler. The second sentence is slightly redundant with the name but does carry cross-tool context.

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?

No output schema exists, so the description should indicate what is returned (a plain commit message string, subject line only or subject plus body). It omits that, and also omits input format guidance for the required diff parameter.

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 50%: the 'style' parameter documents 'conventional'/'plain' and its default, but 'diff' has no schema description and the tool description does not compensate by specifying format (unified diff? git diff output?) or size expectations.

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 ('Generate a commit message for a diff') and explicitly names the sibling it parallels (merjax_generate_pr_description), so an agent can tell the two apart by output artifact.

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?

Implies the use case via 'explicit for the commit-message use case', but never states when to prefer this over merjax_generate_pr_description or what prerequisites (e.g., a diff source) are needed. Guidance is inferable but not spelled out.

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