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

No annotations are supplied, so the description carries the full behavioral burden, and it discloses the cost (USD 0.25) — a genuinely useful trait. However it says nothing about read-only nature, auth, latency, caching, or whether the cost applies per call or per product, leaving the mutation/safety profile undefined.

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, front-loaded with the returned metrics and ending with the cost. The metric enumeration is dense but every item earns its place; nothing is padded or redundant.

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 must explain what comes back — and it lists the returned metrics explicitly, plus the price. For a two-parameter read/analytics tool, an agent has what it needs; only the missing usage guidance is a gap, scored elsewhere.

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 both 'producto' (with example) and 'pais' (with enum list) are already documented in the schema. The description adds no meaning beyond that, so the baseline 3 applies.

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 (a product's market on Mercado Libre) and enumerates exactly what is computed: min/p25/median/p75/max price range, % with FULL shipping, % official stores, and seller concentration. It is not a tautology of the name. It does not explicitly contrast with siblings like informe_oportunidad, but the metric list is distinctive enough to separate it.

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?

There is no when-to-use guidance, no prerequisites, and no mention of when an agent should prefer informe_oportunidad or mas_vendidos instead. The only extra info is the price, which does not help select the tool.

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