compare_products

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it discloses what happens when articles are not returned ('listed with a reason'), and enumerates the data fields delivered. This gives the agent a realistic expectation of response completeness without needing to inspect the output schema.

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 first sentence front-loads the tool's capability and key output fields; the second adds an important edge-case behavior. Every word contributes to an agent's understanding.

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 moderate complexity (2 params, 1 required, output schema present), the description is complete. It states the upper bound (20), the data returned, and the fallback behavior for missing articles. The output schema covers return structure, and the city parameter is documented in the schema. There are no critical gaps that would prevent correct invocation.

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%, with both 'articles' and 'city' already described in the schema. The description mostly reiterates the maxItems=20 constraint and provides a list of returned fields, but does not add new meaning about parameter formats, city syntax, or article identifier types. Baseline 3 is appropriate because the schema carries the semantic burden.

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 uses a clear verb-resource structure: 'Up to 20 articles side by side in one request' immediately identifies a batch comparison tool. It lists specific output dimensions (price, discounts, promotions, stock, delivery), which distinguishes it from siblings like get_product (single product) and search_products (search). The resource and scope are unambiguous.

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 when to use it: when you need multiple articles compared in one request, with up to 20. It does not explicitly name alternatives or state when not to use it, but the context is clear enough for an agent to select it over get_product for batch comparison tasks. Minor gap: no explicit exclusion guidance.

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