create_milestone

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

The description adds two genuinely valuable behavioral details beyond the annotations: that the milestone is created as 'open' (vs closed), and that the description is sent via stdin and not written to the audit log. This latter point is a meaningful and non-obvious transparency disclosure. Annotations cover readOnly=false, so the mutation intent is clear, but the stdin/audit-log detail goes well beyond annotation coverage.

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?

Two sentences, both dense with value. The first sentence states purpose and scope; the second delivers a non-obvious behavioral detail. Zero filler words, efficient structure.

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 tool with no output schema and sparse annotations, this description covers the key behavioral points an agent needs: what it creates, the state, permission context ('allowed repository'), and the audit-log caveat. The main gap is that it doesn't address what success/return looks like, which the missing output schema could have covered. Given the low schema coverage and no output schema, this is reasonably complete but not exhaustive.

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 very low (17%) with 6 parameters, so the description must compensate. The description clarifies that 'description' is sent via stdin and excluded from the audit log, which adds meaning beyond the plain schema field. It also clarifies milestone state ('open'). However, it doesn't explain dueOn format, title constraints, or hostname semantics beyond what the schema already shows, though the schema mostly documents these.

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 verb 'create' plus resource 'milestone' clearly states the action, and 'an open milestone in an allowed repository' adds scope context. It distinguishes itself from the sibling update_milestone since it explicitly says 'create' and 'open', though it doesn't name the alternative directly.

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 implies usage context ('in an allowed repository') which hints at permission prerequisites, but provides no explicit when-to-use vs alternatives guidance. It doesn't mention when this should be used over update_milestone or other tools, nor any preconditions like needing repository edit permissions.

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