Reopen a GitHub issue

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

Beyond the annotations, it discloses that followers are notified, that the comment is posted as part of the reopen, and precisely what the no-op branch does (nothing sent, comment discarded, changed false). Those side-effect details are exactly what annotations like destructiveHint and idempotentHint cannot convey.

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-loaded with the action and its side effect, followed by the no-op case and then the identifier formats. The identifier-format sentence duplicates the schema, which is the only waste.

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 three-parameter mutation tool with full schema coverage and an output schema, the description covers the state transition, side effects and the idempotent branch. Only permission or auth requirements are unaddressed, which is a minor omission at this complexity.

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 accepted issue formats and the repo default rule are already documented in the schema; the description largely restates them. It adds no format or interpretation detail beyond the structured fields, so baseline 3 applies.

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 ("Reopen a closed issue") and the closing clause scopes it to closed issues only. An agent can distinguish this from github_issue_close or github_issue_comment without opening any schema.

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 clearly frames the operating condition (only closed issues are affected) and spells out the no-op branch when the issue is already open. It does not name an explicit alternative such as github_issue_comment for comment-only flows, so it stops short of full alternative routing.

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