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

The description discloses the full behavioral impact: marks pass invalidated, rebuilds .pkpass with Apple's voided flag, and sends push notifications. It also states the required scope (passes:manage) and API path, adding substantial context beyond the destructiveHint annotation. No contradiction with annotations.

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 well-structured and front-loaded with the core action. Each sentence adds information about effects, scope, API mapping, or constraints. It is slightly verbose but not redundant, and the logical flow aids comprehension.

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?

The description covers the action's outcome, scope, API path, and constraints (e.g., 'do not invent other paths'). It lacks explicit error-case handling, but for a destructive mutation with annotations indicating non-idempotence, this is sufficient for an agent to call it 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 input schema already provides detailed descriptions for all three parameters (100% coverage). The description adds a note about wallet_type default and purpose, but that is already present in the schema. It does not provide significant additional semantic value beyond what the schema offers.

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 clearly states a specific verb (void) and resource (pass by serial number), and explains the effect (marks invalidated, rebuilds .pkpass with voided flag). It also distinguishes this tool from siblings like voidPass by specifying serial-number lookup, and clarifies the wallet_type selection for dual-wallet serials.

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 gives explicit guidance on when to use the wallet_type parameter (when a serial has both Apple and Google passes) and notes the default behavior. It provides scope and API mapping, but does not explicitly mention alternative tools like voidPass for ID-based voiding, leaving some usage context implicit.

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