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

Annotations are minimal (readOnlyHint=false, destructiveHint=false), so the description carries the behavioral burden. It says 'verify' but does not disclose side effects such as crediting the user, consuming the transaction, idempotency, or failure behavior. This is a significant gap for a server-side verification call that may mutate state.

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?

One concise sentence with no redundant phrasing. Required parameters are listed compactly and the platform enum is naturally embedded in the prose.

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 format is covered. The description names the operation, platforms, and required inputs, but lacks context about when to call it after a client purchase, the source of tokens, and what happens on success or failure. Given the large sibling toolset, this leaves some selection ambiguity.

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 0%, so the description must compensate. It lists all five parameters and adds a conditional rule ('purchaseToken for Android') that clarifies the otherwise-optional schema field. However, it does not explain the meaning of packageId/transactionId/productId beyond their names, so compensation is partial.

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: 'Server-side verify of RevenueCat / store purchase', and names the platforms (iOS/Android). This distinguishes it from sibling verifiers like ucode_payments_stripe_verify, so an agent can tell it applies to app-store/Play purchases.

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 context ('same as mobile') but does not explicitly name sibling alternatives or state when not to use this tool. Usage is implied by the purpose rather than clearly routed against the numerous payment and credit siblings.

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