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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds genuine context beyond that: data provenance ('sourced from Best Buy's own store directory') and the shape of each record. It does not mention result counts, pagination, or coverage limits, so it is not exhaustive.

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 front-loaded sentences: the first states what the tool returns, the second defines the inputs. Efficient with no filler, though the field enumeration is somewhat redundant given an output schema exists.

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?

An output schema exists, so return values need not be re-explained, and annotations cover the safety profile. Parameters are fully documented. The definition is complete enough to invoke correctly; only pagination/coverage details are absent, which is minor.

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?

With 0% schema description coverage, the description must carry the parameters, and it does: state is defined as a two-letter US state/territory code with the example 'il', and city is described as free text matched against that state's directory with the example 'Chicago'. This conveys both format and the state->directory matching behavior, adding real value over the bare schema.

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 a specific resource (Best Buy physical store locations), the exact scope (one city), and enumerates the fields returned (name, address, phone, coordinates, rating, hours). An agent can immediately tell this is a per-city store-locator, distinct from bestbuy_product or bestbuy_search.

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 scope 'in one city' implies the intended use, and the state/city requirement signals the calling context, but there is no explicit when-to-use/when-not guidance and no sibling is named as an alternative. Usage is inferable rather than stated.

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