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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds valuable behavioral context: cost per successful call, payment rails (Base, Solana, Arc), and that failed calls are free—critical for agent decision-making. It does not cover rate limits or auth details beyond x402, but this is a strong addition over the annotations alone.

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?

The description is a single dense sentence with many comma-separated clauses listing return fields, some of which duplicate the output schema (e.g., prices, rating, flags). It is front-loaded with the store and action, but the field enumeration makes it longer than necessary for an agent that already has the output schema.

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?

Given the tool's simplicity (2 parameters), the presence of an output schema, and read-only annotations, the description is fairly complete. It covers search scope, pricing, and return highlights. It could be improved with explicit guidance on sibling alternatives, but nothing critical for correct 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 two parameters (q and page) are fully documented in the schema. The description does not add meaning beyond what's already in the schema—e.g., it repeats that search words are in Spanish or English, and doesn't elaborate on pagination behavior beyond the schema's page 1–50 range.

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 states a specific verb (product search) and resource (Falabella Chile products), and enumerates returned fields. It distinguishes itself from sibling ecommerce tools by naming the store, but does not explicitly contrast with alternatives like ecommerce_amazon or ecommerce_lazada.

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 store name and product search context, but the description never states when to choose this tool over the many other ecommerce search siblings. The pricing model ($0.002 per successful call, x402 payment) is mentioned, which indirectly informs usage decisions, but no explicit alternatives or exclusions are given.

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