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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description usefully adds that the response embeds variants and images (important since there is no output schema) and maps to a concrete endpoint, but says nothing about not-found behavior or whether nested collections are truncated or paginated.

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 short, front-loaded sentences with no filler; the resource and payload come first. The raw endpoint string is mild redundancy but still earns its place as an API-mapping hint.

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 a one-parameter read tool this is close to adequate, and it does gesture at return contents. With no output schema, though, an agent still lacks detail on response shape and on whether the nested variants/images are complete or paginated.

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?

A single parameter with 100% schema description coverage ('Sapo product id.', type integer, >0), so the schema already does the work. 'By id' in the description adds no format or lookup guidance beyond that.

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?

Specific verb+resource: retrieves exactly one product by id, and it names the payload contents (variants and images). That makes it distinguishable from the plural sapo_list_products, even though no sibling is called out by name.

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 or when-not-to-use guidance and no mention of alternatives such as sapo_list_products for browsing or sapo_get_product_variant for a single variant. The only implied condition is 'you have a product id'.

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