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

Goes beyond the annotations by disclosing the external side effects: PR Explanation 'posts nothing to GitHub' while Code Review 'posts its findings as review comments on that pull request.' It also explains idempotency semantics concretely (same key = same execution), which adds value on top of idempotentHint=true. It does not mention auth/permission requirements for the live-authorized repo, keeping it short of a 5.

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?

Four tight sentences, front-loaded with what the tool does, then the two task behaviors, then the prerequisite, then the idempotency contract. No filler or restatement of the title.

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?

An output schema exists, so return values need no explanation; the description instead covers the things it must: which task templates are valid, the pre-condition for calling, the differing GitHub side effects, and retry semantics. Nothing material for correct invocation 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 80%, so the schema already documents task_id, idempotency_key, organization_id, pull_request fields and the audience enum. The description reinforces only the 'exact pull-request revision' constraint already captured by expected_head_sha; it adds no format or edge-case guidance for the remaining parameters. 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 (Start) and resource (one first-party task from list_tasks) and pins the scope to an exact pull-request revision. It also enumerates the two task kinds it can launch and what each does, so an agent can distinguish it from start_workflow without opening the 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?

Gives an explicit gating condition: 'Call only after the user explicitly asks to run that task in the current turn,' and points at list_tasks as the source of task_id. It does not, however, route the agent away from the sibling start_workflow or explain when a workflow run (rather than a task) is the right choice.

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