Create label

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

Beyond the annotations, the description discloses that one mutation attempt is followed by authoritative semantic readback, that it never overwrites or retries ambiguous creates, and that it does not edit issues or delete labels. This adds significant behavioral context regarding auth, scope, and post-action verification.

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 sentences front-load the core purpose and then concisely add critical behavioral details. Every sentence earns its place; there is no fluff or repetition of schema content.

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 mutation tool, the description covers auth, non-idempotency, exact scope, post-write readback, and what it avoids. With a full schema and output schema present, the description is complete enough for an agent to select and invoke the tool 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 coverage is 100% with each parameter described. The description adds that name, color, and description are 'explicitly bounded,' which reinforces but does not extend the schema constraints. It does not add new parameter-specific semantics beyond the schema.

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 uses a specific verb and resource ('create exactly one new repository label') and clearly distinguishes from siblings by stating it does not edit issues or delete labels. The scope is unambiguous.

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 provides clear context: it is additive, creates one label, and never overwrites an existing label, implying that editing should be done elsewhere. It also notes ordinary write authorization as a prerequisite. It does not explicitly name alternative tools, but the exclusions help an agent decide when not to use it.

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