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

Annotations already cover the safety profile (readOnly, non-destructive, non-open-world), and the description adds genuine context beyond them: exact-amount handling, strict grouping, per-price error reporting, the 50-item cap, and that no key/credits/wallet are needed in free mode. It does not, however, explain the unusual idempotentHint=false for what looks like a pure normalization operation.

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?

Front-loaded with the core action and its limits, followed by two short sentences on cost and constraints. Slightly telegraphic phrasing ('exact amounts, strict grouping and per-price errors') but no wasted sentences.

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 values need not be explained, and the description covers limits, free-mode behavior, and error semantics adequately. It leaves the non-idempotent annotation and the legacy parameter handling unaddressed, which keeps it short of a 5.

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?

At 67% schema description coverage, the schema carries most of the parameter burden, and the description's mention of locale, currency and decimal scale just restates the required nested fields. The legacy requestId/maxPriceMicroUsd fields are documented only in the schema, so the description adds no compensating detail.

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?

States a specific verb and resource ('Normalize ... displayed prices') plus scope ('up to 50', 'explicit locale, currency and decimal scale'). This clearly separates it from adjacent siblings like commerce_price_components and commerce_unit_price, which decompose rather than normalize whole displayed prices.

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 no when-to-use or when-not-to-use guidance and names no alternative tool. The 'FREE during validation' line describes pricing/access, not the conditions under which this tool should be selected over siblings such as commerce_price_components.

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