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

The annotations already establish read-only, idempotent, non-destructive behavior. The description adds useful context about the dependency on gate_transaction and the source of the price, but it does not explain behavior when the decision is not 'allow', when no offers exist, or how market affects the result.

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 short and mostly front-loaded, but the final sentence 'Tiers buy services, never rank' is opaque and unexplained, making it a confusing inclusion. The structure is not as clean as it could be.

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?

The description provides the core precondition and price source, and an output schema exists, but it omits clarification for gtin and market and does not state what happens in edge cases. It is adequate for a straightforward read, but not fully complete.

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 description coverage is 0%, so the description must compensate; it meaningfully explains decision_id as the gate_transaction decision, but it does not explain gtin or market. The parameter names may be conventional, but the description leaves important invocation semantics undocumented.

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 identifies the tool as returning a price for a buyer, with the price basis coming from supplier offers and conditioned on a gate_transaction decision. It is specific enough to be distinguished from generic price tools, though the phrase 'Tiers buy services, never rank' is cryptic and adds little clarity.

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 states the key precondition: use this tool once gate_transaction has answered allow with a decision_id. It does not name alternatives or state when not to use it, but it does convey a clear sequencing requirement.

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