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

Annotations already declare readOnly, idempotent, non-destructive, and open-world, so the safety profile is covered. The description adds genuine value beyond that: newest-first ordering, 30-per-page pagination, the exact returned fields, co-author extraction, and AI-agent detection. It stops short of describing page-boundary or truncation behavior, which keeps it from 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?

The scoping and return-shape information is front-loaded in a single dense sentence, followed by a short usage line and the cost note. Every element earns its place, though the trailing "Free." fragment reads as an afterthought rather than integrated 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?

With no output schema, the description correctly compensates by enumerating the returned fields (subject, date, link, co-authors, AI-agent flag) and the ordering. For a 3-parameter read-only list tool with full schema coverage and rich annotations, that is nearly everything an agent needs; only cross-repo/alternative routing is missing.

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% and the schema already explains username, repo format (owner/name or URL), and page numbering. The description's "one repo (theirs or anyone's)" and "30 a page" largely restate the schema rather than adding syntax or edge-case guidance, so the 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?

States a specific verb (list) and resource (commits) with clear scope: one developer, one repo, either their own or anyone's. It also previews the return fields, so an agent knows exactly what comes back. It doesn't name sibling tools like search_commits or list_pull_requests, so differentiation is inferential rather than explicit.

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?

"Use it to see what they did in a project and how they work" gives a positive usage context, and "Free" signals a cost tier that may matter when choosing between tools. However, it never states when not to use it or which sibling (search_commits) to prefer for cross-repo or filtered queries, leaving the agent to infer the boundary.

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