Add an issue note

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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the safety profile is partly covered. The description adds that the operation is additive/append-only and leaves other data untouched, but omits permissions, response shape, and any note-visibility behavior beyond the schema's private_notes flag.

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?

A single sentence that front-loads the action and immediately qualifies scope. Every clause earns its place with no redundancy.

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 simple three-parameter append tool with full schema coverage and annotations covering the safety profile, the description is sufficient, and an output schema is absent so return values need no explanation. It could say slightly more about whether private notes are visible to the issue author, but nothing essential is missing.

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 all three parameters (id, notes, private_notes) are documented in the schema. The description adds no parameter-level detail, so this sits at the baseline where the schema does the heavy lifting.

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?

States a specific verb and resource ('Appends a journal note to an issue') plus a behavioral scope clause ('without changing anything else') that distinguishes it from the mutation-oriented siblings like issues_update and issues_create. It does not name a sibling explicitly, but the delta 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?

Use is implied: reach for this when you want to add commentary rather than modify issue fields, which is why it is separate from issues_update. There is no explicit when-to-use, when-not, or named alternative, so guidance stops at inference level.

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