create_label

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

With annotations present (openWorldHint: true), the description goes beyond by noting that it changes remote GitLab state, requires permissions, and returns specific error types instead of silently applying invalid requests. This is useful context. It does not mention idempotency or reversibility, but given the annotation, the bar is lower. The description adds value.

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 paragraph but covers multiple aspects: purpose, usage distinction, permissions, errors, and ID handling. It is not overly long, but the sentence structure could be tighter. It front-loads the purpose and usage distinction, which is good. Slight redundancy in mentioning permissions and errors twice, but overall concise enough.

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 create operation with 5 parameters, 100% schema coverage, and no output schema, the description adequately covers purpose, usage, permissions, and error behavior. It does not explain the return value, but since there is no output schema, that is expected. It also does not list prerequisites like existing project existence, but that is implicit. Overall, it is complete for an agent to call this correctly.

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%, so each parameter is already documented. The description adds guidance on how to format project_id (numeric ID or URL-encoded path) and emphasizes using exactly as documented for identifiers and pagination fields, but it doesn't add new semantic details beyond the schema. 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?

The description states the verb 'Create', the resource 'label', and the container 'project', which is clear. It distinguishes from update/edit tools by indicating when to use the create version. It could be slightly sharper about whether group labels are supported (the description mentions group permission, but the schema only has project_id), but overall the purpose is clear.

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 to use this for a new resource and to choose the update/edit tool when the resource already exists. It also mentions permissions and errors, and provides guidance on how to provide identifiers. However, it does not elaborate on when to use a group path versus a project ID, despite mentioning group permission. This is a minor gap.

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