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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the description earns credit for adding methodology: prices are official SIPC/MEF data, the ranking uses a matched basket of 33 items and is 'never by gross total', and item results report tier and store count. That caveat meaningfully prevents misreading the ranking. It stops short of noting data freshness/update cadence, which would push it higher.

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 filler: the two capabilities come first, the methodological caveat is attached to the ranking it qualifies, and the use case closes. The parentheticals are dense but each carries real information.

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?

For an all-optional, three-parameter read tool with no output schema, the description conveys enough about what comes back (price tier, store count, ranked supermarkets per department) to call it correctly. Return shape and ranking criteria details remain unspecified, but nothing essential to invocation is missing.

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 description coverage is 100%, so the three parameters (text, limit, department) are fully documented in structured form and a baseline 3 applies. The description reinforces the item-vs-department split but adds no syntax or formatting detail beyond what the schema already supplies.

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 concrete verb+resource: official SIPC (MEF) prices per item with price tiers and store counts, plus cheapest-supermarket ranking per department. The dual output mode (item lookup vs. department ranking) is spelled out, which lets an agent distinguish this from siblings like search_products or estimate_fair_rent, though no sibling is named explicitly.

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 closing phrase 'Útil para estimar el costo de vida al mudarse' implies a use case, and mentioning that text targets a single article while department drives the ranking hints at when each parameter applies. But there is no explicit when-to-use/when-not guidance and no routing to alternative tools (e.g., search_products, estimate_fair_rent, rank_rentals_for_household) that could also serve cost-of-living questions.

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