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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful context about resolving fiat display rather than exposing raw IDs, but it does not disclose additional behavioral details such as error handling or invalid-ID behavior.

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 compact, front-loaded with the rare-usage warning, and contains no filler. Every clause earns its place, and the key caution is immediately visible.

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 one-parameter read-only lookup with complete schema coverage and an output schema present, the description plus annotations fully cover safety, usage, and alternative routing. Nothing essential 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?

The input schema already fully documents the single parameter: 'Comma-separated Stripe price_… or prod_… IDs'. The description reinforces the prod_/price_ distinction but adds no new parameter semantics beyond the schema.

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 names a specific operation ('Resolve fiat display') and a specific resource ('Stripe IDs'), and it explicitly contrasts this tool with ucode_credit_packages for storefront-style copy. An agent can distinguish it from the many payment/credit siblings without opening schemas.

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 marks the tool as rare, states its intended use, and gives explicit when-not-to-use guidance: do not read raw prod_/price_ strings to end users. It also names the alternative tool, ucode_credit_packages, for storefront-style copy. This is full routing guidance.

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