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 genuinely useful behavior beyond that: unresolvable searches and zero-result radii return a well-formed empty result rather than an error, which shapes how the agent should interpret responses.

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 tight sentences with no filler; the locator purpose and the input-mode constraint are front-loaded ahead of the edge-case behavior.

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?

With an output schema present, return values need not be described. The description covers identity, both input modes, the required-parameter combination, and the empty-result edge case, leaving nothing an agent needs to call it correctly.

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 per-field descriptions exist, so the baseline is 3. The description goes further by articulating the cross-parameter rule (search alone, or lat+lng together) that the schema's 'required: 0' does not express, adding real semantic value.

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?

States a specific verb+resource+scope: 'H&M physical retail store locator', and enumerates returned fields (name, phone, address, coordinates). It is instantly distinguishable from siblings like hm_search, hm_product, and hm_listing, which cover catalog rather than physical locations.

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?

Explains the two supported lookup modes (free-text zip/place vs. direct lat/lng) and the constraint that either search or both lat+lng is required, which tells the agent how to drive the tool. It does not name competing sibling tools or state when not to use it, so it falls short of a full 5.

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