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

Annotations already indicate destructiveHint=true, but the description adds valuable behavioral detail: it explains the push notification side effect, the non-fatal rebuild failure (pass is still invalidated at DB level), and the scope. These details go beyond the annotations and give the agent a clear picture of consequences.

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 concise and well-structured: a clear heading, two sentences on effect, a bullet for scope and API mapping, and a final warning. Every sentence adds value, and the most important information (voiding effect) is front-loaded.

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 destructive mutation with no output schema, the description covers the essential aspects: what happens (invalidation, rebuild), side effects (push notifications), failure tolerance (non-fatal), and API binding. It could mention the response format, but since there is no output schema, this is not a critical gap. Overall, it is complete for an agent to invoke correctly.

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?

The schema already provides 100% coverage with descriptions for both id and x_app_id. The description does not add parameter-specific details, which is acceptable given the high schema coverage. It mentions the API path and scope but not parameter semantics, so it stays at 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 opens with 'Void a pass' and immediately clarifies the exact resource and action: marks a pass as invalidated and rebuilds the .pkpass with Apple's voided: true flag. It clearly distinguishes from sibling voidPassBySerial by focusing on the pass ID and the API path, so an agent can differentiate 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?

The description provides explicit usage context: it states the required scope (passes:manage), maps to the exact OpenAPI operation and endpoint (POST /manage-passes/{id}/void), and warns not to invent other paths. It does not explicitly compare with alternatives like voidPassBySerial, but the context is sufficient for an agent to understand when to call this tool.

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