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

The annotations already declare readOnlyHint, destructiveHint=false, idempotentHint, and openWorldHint, so the safety profile is covered. The description still earns credit for two things annotations cannot express: that only public data is touched and that each request costs 1 credit, which matters for call budgeting. It omits the 1,000-result pagination ceiling, though the schema's start parameter covers that.

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?

Three short sentences, each doing distinct work: purpose, safety/scope, and cost. The purpose statement is front-loaded and nothing is padded or repeated from the structured fields.

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 13 parameters, nested date filters, and no output schema, the definition is arguably under-specified about what a returned commit record contains and whether the credit cost scales with pagination. The description is adequate for correct invocation because the schema is exhaustive, but an agent has no picture of the response shape.

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 100%, with every parameter documented inline including the hash/author/committer/repo qualifier mappings and the date-range nested objects. The description adds no syntax or interpretation guidance beyond the schema, so the baseline of 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 names a specific verb and resource ("Search commits") and constrains scope to public GitHub repositories, which cleanly separates it from github_search_code, github_search_issues, and github_search_pull_requests. It stops short of explicitly naming those siblings or the conditions that would pick one over the other.

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?

There is no when-to-use or when-not-to-use guidance beyond the implied scope of "public repositories." The agent must infer on its own whether to reach for commit search versus code search, issue search, or a repository listing when investigating a project.

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