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

Beyond the annotations (idempotentHint=true, readOnlyHint=false), the description discloses the cost (300 micro-dollar credits per call), the requirement for a private Authorization header, and the recovery behavior (reuse requestId to avoid new charges). It also mentions per-price errors, indicating partial success/failure granularity. This adds substantial behavioral context that annotations alone do not provide.

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 a compact paragraph where every sentence adds value: purpose, cost, prerequisite, and recovery behavior. The key purpose is front-loaded, and the technical details are efficiently packed. No filler or redundancy.

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?

Given the tool's complexity (paid service, requires a prep step, has an output schema), the description covers all critical aspects: what it does, cost, prerequisites, recovery pattern, and error granularity. It does not describe the output format, but an output schema exists, so that is not required. The description is sufficient for an agent to use the tool 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?

Schema coverage is 67% (requestId and maxPriceMicroUsd have descriptions, input does not). The description echoes the locale, currency, and decimal scale from the schema but adds no new parameter details. The 'up to 50' limit is already in the schema's maxItems. The description does not clarify the meaning of input fields beyond what the schema enums and types convey, so it meets the baseline but does not enhance understanding.

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 the verb 'Normalize' with a specific resource ('displayed prices') and scope constraints (up to 50, explicit locale/currency/decimal scale). It also mentions exact amounts and per-price errors, which distinguishes it from sibling tools like commerce_unit_price or commerce_price_components that handle different aspects of pricing.

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 explicitly instructs to use agent_utilities_prepare first and explains the recovery pattern (reuse requestId, new requestId = new billable operation). It also states prerequisites (existing credits, Authorization header). It does not explicitly name alternatives or say when not to use it, but the prerequisites and purpose are clear enough for an agent to decide. Lacks explicit exclusions compared to other tools, so not a 5.

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