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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered elsewhere. The description usefully discloses what data is actually returned (delivery area, fee, threshold, payment methods), but says nothing about whether this is static store-wide policy versus per-order or per-region data, nor about freshness or caveats.

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?

A single front-loaded sentence that enumerates the covered topics with no preamble, filler, or repetition. Every clause maps to information the agent would actually need to know is available.

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?

There is no output schema, so the description carries the burden of describing return content, and it does so by enumerating the four information categories. For a static, read-only, single-optional-parameter lookup tool this is close to sufficient; only the shape of the answers (structured fields vs prose) is left unspecified.

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 coverage is 100% and the single optional 'language' parameter is fully documented in the schema with its allowed values and default. The description therefore adds nothing about parameters, and baseline 3 applies; mentioning that output language is controllable would have been a modest improvement.

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 names the resource and enumerates its scope precisely: delivery area, delivery time and fee, free-delivery threshold, and accepted payment methods. An agent can distinguish it from browse_category, get_product, or current_deals without ambiguity. It is a content list rather than a verb+resource phrasing, which is the only thing keeping it from 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?

Usage is implied by the content enumerated: an agent should call this for questions about shipping, delivery costs, or payment options. There is no explicit when-to-use statement, no exclusion, and no named alternative among the siblings, though no sibling meaningfully overlaps this scope.

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