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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds behavior beyond that: supplying an item name augments the response with links to check today's price, which is genuine output-variation disclosure. It omits auth needs, rate limits, and freshness of policy data, keeping it out of 5 territory.

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 purpose in a single sentence, then example queries, then the optional-item modifier. The example list is somewhat long, but each query disambiguates a real phrasing an agent might encounter, so it earns its space.

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 3-parameter read-only tool with no output schema, the description covers what is returned (the store's policy, plus optional price links) and the schema carries the country_code nuance. Nothing critical is missing, though a note on policy freshness or store-not-found behavior would complete 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?

Schema description coverage is 100%, and the schema already explains 'item' (optional, up to 100 chars, links today's prices), 'store', and the country-code defaulting logic. The description's note that an item name 'adds links to check today's price' mostly restates the schema, so the baseline 3 is correct.

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 resource and scope: a store's price adjustment and price match policy, retrieved by store name. Example queries ('does Target do price matching?', 'Currys price promise') make the retrieval intent unmistakable. It does not name its siblings (check_price_drop_claim, list_stores), so it earns a 4 rather than a 5.

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?

Five concrete example queries effectively define when this tool applies, which is stronger than implied usage. However, there is no exclusion guidance or explicit routing to the alternatives: it never says to use check_price_drop_claim instead when the user wants to file a claim rather than read a policy.

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