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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds genuinely non-structured context: that each entry carries terms and a policy page, and critically that a missing retailer means 'unverified, not a no' – a subtle interpretation rule the agent could not infer from annotations or schema.

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?

Two sentences, zero waste. The scope and return shape are front-loaded, and the second sentence delivers the single most important interpretive caveat without padding.

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 simple, read-only, no-output-schema tool, the description explains what is returned, how filtering works, and how to read an empty/partial result. That is close to complete; the only gap is the absence of explicit routing relative to its siblings.

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 100%, with country (ISO 3166) and category examples already documented in the schema itself. The description only restates that these filters are optional, adding no syntax or meaning beyond the schema, so the baseline 3 applies.

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 states a specific verb ('Returns'), a precise resource ('retailers whose price-match policy a person has verified'), and the shape of each result. It is clearly a registry/list lookup, which implicitly separates it from the judgment-oriented siblings (will_price_match, can_make_offer), though it never names them.

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?

It conveys that filtering is optional via category and country, so an agent knows it can call with no arguments, but it gives no explicit when-to-use guidance against the siblings like will_price_match or price_policy. The useful absence-semantics note is about interpreting results, not about selecting this tool.

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