create_issue_note

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

The description discloses that the operation creates remote discussion content, requires note permission, and returns either the note or specific missing-issue/thread/permission errors. Since annotations only include `openWorldHint: true`, this behavioral detail adds meaningful transparency beyond structured data.

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 compact at three sentences and front-loads the core purpose, but the second sentence partially repeats the first ('Add a note to an issue' vs 'add a note to an existing issue'). Minor redundancy keeps it from being maximally concise.

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 straightforward 5-parameter create operation with no output schema, the description covers the operation's effect, permission requirement, error returns, and alternatives. It does not elaborate on `created_at` behavior, but the schema already describes the parameter.

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%, so the schema already documents parameters clearly. The description adds semantic value by tying `discussion_id` to the optional-reply behavior and clarifying the topic of notes versus generic notes, which enriches parameter understanding without repeating 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 clearly states the verb-resource pair: 'Add a note to an issue,' with an important qualifier, 'optionally replying to a discussion thread.' It distinguishes itself from nearby siblings by explicitly calling out `update_issue` for issue fields and `create_note` for the generic endpoint.

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 explicit when-to-use guidance and names alternatives: use this for notes on issues, use `update_issue` for issue fields, and use `create_note` only when the generic endpoint is required. This is clear and actionable routing.

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