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

Annotations already declare readOnly/idempotent/non-destructive/non-openWorld, so the safety profile is covered. The description adds real behavioral value by disclosing the return content, notably 'when not to recommend it' and 'third-party coverage and sources', which tells the agent this is a decision-support payload, not just a record fetch. It doesn't cover absence/error behavior, keeping it from a 5.

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 front-loaded sentence that names the resource first and then enumerates contents; each item earns its place as a signal of what the payload contains. The colon-list is dense but not padded.

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 carry return-value meaning and it largely does by listing the data categories returned. Gaps remain around response format, sourcing of 'third-party coverage', and failure behavior for an unknown id.

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?

One parameter at 100% schema coverage, and the schema already documents 'Product id from search_products'. The description adds no parameter-level detail (id format, casing, validation) so the baseline 3 for fully-covered schemas 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?

States a specific verb+resource ('full facts for one product') and enumerates exactly what is covered: prices, ratings with dates, features, attributes, negative-recommendation signals, coverage and sources. The singular 'one product' implicitly contrasts with search_products/compare_products, but no sibling is named, so it stops short of a 5.

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 never says when to use this versus list_attributes, search_products or compare_products, nor when not to use it. The only routing hint ('Product id from search_products') lives in the schema, not the description, leaving the agent to infer the search-then-fetch workflow.

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