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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the description's job is to add context — and it does: it discloses that results are verified brick-and-mortar stores with in-stock products, unit prices, and Haversine distance in kilometers. It omits fallback behavior when customer_lat/lng are absent and says nothing about result ranking beyond proximity.

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 sentences, zero waste. The capability statement comes first and the return-value summary second, which is the right ordering for an agent deciding whether to call it.

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 no output schema, the description correctly compensates by enumerating what comes back (stores, in-stock products, unit prices, distance). The one gap is the optional-location case: a tool framed entirely around GPS proximity never explains how ranking degrades without coordinates.

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%, so all five parameters are already documented, and the baseline of 3 applies. The description adds only marginal value beyond the schema — it confirms distance is Haversine in kilometers, but does not explain the consequence of omitting the optional coordinates or how max_distance_km interacts with them.

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 and resource: searching real-time physical retail store inventories ranked by a shopper's GPS location. This is unmistakably different from the siblings (check_order_status, create_order, report_store), which are order/feedback tools rather than discovery tools.

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 phrase 'near a shopper's GPS location' and the product-query framing, but the description never states when to prefer this over alternatives or when not to use it. No prerequisites, no exclusions, and no mention of what happens if location inputs are omitted.

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