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

Annotations already declare destructive=true and idempotent=false. The description adds useful context by stating the merge applies immediately and documenting two failure modes: RESOURCE_LIMIT_REACHED and SERVICE_UNAVAILABLE naming the failed step.

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 front-loads the core action, then adds immediacy and error behavior without filler. Every sentence contributes useful operational context.

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?

With an output schema present and annotations covering destructive/idempotency, the description supplies purpose, immediate effect, and error behavior. It omits merge preconditions such as required approvals or mergeability, which is a minor gap for a destructive merge tool.

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 both ledger and prNumber are already documented in the input schema. The description does not add syntax or format details for either parameter beyond what the schema provides, making 3 the baseline.

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 states a specific verb and resource: "Merge a pull request into its base branch." This clearly distinguishes the action from siblings like createPullRequest and rejectPullRequest.

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 immediate application wording implies this is the final merge action, but the description does not explicitly say when to use it versus rejectPullRequest or what PR preconditions must be met. Usage is implied rather than fully guided.

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