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

Beyond annotations, the description discloses key behavioral facts: each successful call debits 500 micro-dollar credits, a new requestId starts a new billable operation, and calling requires existing credits plus a private Authorization header. This is exactly the kind of non-obvious operational context an agent needs and nowhere in the 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?

Three sentences, each earning its place: purpose, cost, prerequisite, and recovery rule. Critical billing and workflow warnings are front-loaded while the recovery nuance is added last without bloat.

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 output schema already covers return shape, the description covers everything an agent needs to call the tool safely: purpose, prerequisite preparation step, authorization requirement, billing semantics, and recovery behavior. The complexity here is moderate and the description adequately addresses it.

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 schema already documents requestId and maxPriceMicroUsd well, covering 67% of parameters. The description adds meaning to the undocumented 'input' object by framing its nested fields as 'requested' and 'offered' product attributes, and it reinforces the billing/recovery relevance of requestId and maxPriceMicroUsd. Still, it leaves the nested object semantics only lightly specified, so it does not fully compensate for the remaining schema gap.

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 opens with a specific verb and resource: it compares requested product attributes against an offered variant and reports missing or mismatched fields. This makes the tool's core function immediately clear and distinct from commerce_* siblings like commerce_offer_extract or commerce_price_components, which serve different purposes.

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 workflow guidance: call agent_utilities_prepare first, ensure credits and a private Authorization header exist, and reuse prepared arguments for recovery within the same requestId. It does not explicitly state when to avoid this tool or name a direct alternative, but the prerequisites and payment conditions are strong enough to guide an agent.

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