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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds real behavioral detail absent from annotations: cheapest-first ordering by price per kg/litre/unit, median per store, promotions, and 7/30-day changes. Even though no output schema exists, it discloses the shape of results and the store-page link.

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 dense sentence, but it is front-loaded with the core concept ('Today's online shelf prices in Guatemalan stores') and every clause carries information. Slightly overloaded with retailer and return-format details, yet no filler.

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 carries the burden of describing returns and does so adequately (ordering, median, promotions, changes, links). Zero required params and full annotation coverage of safety mean little else is missing, though the optional-parameter interplay (q vs basket) could be clearer.

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 only 50% (country and retailer are undocumented in the schema), so the description must compensate. It partly does: the retailer names (Walmart/Paiz/Despensa Familiar, Cemaco, Elektra) give meaning to the retailer param and the basket examples (arroz, pollo entero, cemento, pilas) reinforce basket. However country and the exact distinction between q and basket remain unaddressed.

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 ('find products', 'online shelf prices'), names the geographic scope (Guatemalan stores) and specific retailers, and clearly distinguishes it from siblings like search_news, trade_by_product, or convert_currency. An agent can tell exactly what this returns without opening the 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?

The description implies usage ('find products by words or a household basket item') but never states when to prefer this over alternatives or any exclusions. Usage is inferable but not explicitly guided.

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