create_commit_status

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

Annotations only carry openWorldHint=true, which is minimal. The description adds meaningful behavior details: it changes remote GitLab state, requires permissions, and GitLab returns specific validation/conflict/permission/rate-limit errors rather than silently applying invalid requests. It also notes identifier encoding requirements. It doesn't contradict annotations.

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 a single dense block of four sentences, front-loaded with the core action. It's moderately concise but packs a lot of guidance into one paragraph. Could be slightly tighter, but every sentence contributes meaningful routing or behavioral info.

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?

Given 10 params (3 required), no output schema, and only openWorldHint annotation, the description covers mutation behavior, error handling, permission needs, and identifier formatting. It doesn't mention return values but that's minor for a state-changing tool. It's reasonably complete for the tool's complexity.

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 describes all 10 parameters with detailed descriptions (100% coverage), so the bar is lower. Still, the description adds useful guidance on project_id/group_id formats and the name/context alias relationship, which supplements the schema. It could go deeper on state values, but the enum handles that.

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 states a clear action ('Create or update the status of a commit') with a specific resource ('commit status'), and explicitly contrasts with update/edit tools. It distinguishes from the sibling list_commit_statuses by its mutation-focused wording.

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?

It explicitly says 'Use this for a new resource or action; choose the corresponding update or edit tool when the resource already exists.' This provides both when-to-use and when-not-to-use guidance, plus a mention of required permissions and covered error cases.

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