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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds only the endpoint path; it doesn't mention that all filters are optional, that omitting them counts every product, or that the call reflects live store data.

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 nothing wasted. It is arguably over-trimmed rather than padded, but no sentence fails to earn its place.

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 should convey the return value; it says 'Number of products,' which is adequate, and the fully documented schema covers parameters. What's missing is the zero-filter default and any hint about cost or pagination relevance for a count endpoint.

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% and each of the five filters is documented there, so the baseline is 3. The phrase 'matching the filters' adds no syntax or semantics beyond the schema — no defaults or combination behavior are explained.

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 gives a specific verb and resource ('Number of products matching the filters') plus the underlying endpoint, which clearly separates it from list-style siblings like sapo_list_products. It never names those siblings explicitly, so differentiation is inferred rather than stated.

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 only implied: an agent can infer 'call this when you want a count instead of the records themselves,' but no when-to-use or when-not-to-use guidance is given, and no alternative (e.g. sapo_list_products) is named.

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