Github Create Milestone

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

Annotations only mark readOnlyHint false, idempotentHint false, and destructiveHint false. The description adds a useful failure mode: duplicate titles fail due to per-repository uniqueness. However, it does not clearly state that this is a write operation creating a remote object, nor does it mention permissions or other side effects.

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 only two sentences with no filler, and it front-loads the uniqueness constraint and the alternative tool. The wording 'Opens a milestone' is slightly imprecise, but structurally the description is efficient.

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 6 parameters, low schema coverage, and an output schema present, the description still fails to explain the core creation behavior clearly. It adds the duplicate-title rule and update alternative, but leaves state, due_on, description, and general behavior under-specified.

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 only 17%, with only due_on described. The tool description adds meaning for title uniqueness, but state, description, and the repo fields receive no semantic explanation. Given the low coverage, the description should have compensated but does not.

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 says 'Opens a milestone', which is ambiguous and does not clearly say 'creates a new milestone'. The uniqueness caveat and pointer to github_update_milestone help identify the intent, but the tool is not clearly differentiated from related siblings like github_list_milestones or github_set_issue_milestone.

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 states that duplicate titles fail and that the correct action for an existing milestone is github_update_milestone. This gives a clear when-to-create vs when-to-update rule, though it does not cover broader alternative selection.

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