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

Annotations already declare readOnly, idempotent, and openWorld hints. The description adds useful behavioral context by stating that it returns sha, message, author, and date per commit, and explains the optional filters. This goes beyond the basic safety profile without contradicting it.

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 description is three sentences, tightly packed with purpose, usage guidance, parameter hints, and return details. Every sentence earns its place, and it is front-loaded with the core purpose.

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 read-only commit listing tool with no output schema, the description covers the key elements: what it does, when to use it, key parameters, and return fields. It doesn't explicitly state sorting order or pagination defaults, but the schema already documents per_page, and 'recent' implies recency. Slight ambiguity about ordering prevents a perfect score.

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 baseline is 3. The description adds semantic value by clarifying that 'sha' is a branch/tag/commit to start history from, 'path' limits to commits touching a file/dir, and since/until are ISO timestamps. This complements the schema with more intuitive explanations.

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 clearly states the tool lists recent commits on a repository to show latest activity, what changed, and who is committing. It uses a specific verb and resource, and explicitly contrasts with web search, which helps distinguish it from alternative approaches like web search or other repo tools.

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 description explicitly says 'PREFER OVER WEB SEARCH' for specific query types, providing direct guidance on when to use this tool. It also outlines optional parameters that refine usage, making the intended context very clear.

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