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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorldHint=false, so the safety profile is covered. The description adds a genuine behavioral detail beyond them: supplying an item name augments the response with links to check today's price, which tells the agent how the output changes. No auth or rate-limit context is given.

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 core purpose is front-loaded in sentence one, and the example queries are compact and each illustrate a distinct phrasing. The quoted-example list is somewhat long for the payload it carries, but nothing is redundant.

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 read-only, single-store lookup with full parameter documentation, this is nearly sufficient: the agent knows the resource, the trigger phrases and the conditional item behavior. The only real gap is the response shape, and with no output schema that omission slightly weakens an otherwise complete definition.

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%, so the schema already documents store, item and country thoroughly, including the country-code semantics and defaults. The description only adds that item yields price links, which is marginal on top of the schema's own "to link today's prices for it" wording. Baseline 3 is appropriate.

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 first sentence names a specific resource and scope: a store's price adjustment and price match policy. The follow-up example queries ("does Target do price matching?", "Currys price promise") pin down exactly the intent, so an agent can distinguish it from check_price_drop_claim without opening either schema.

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 phrasings give clear context for when this tool fires, including the conditional use of the item parameter. It never states when NOT to use it or names check_price_drop_claim as the alternative, so routing between the two price-related siblings is left to inference.

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