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

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, so the safety profile is fully covered. The description's only added content is the REST path, which restates that this is a single-resource fetch; it says nothing about error behavior for missing ids, auth requirements, or response shape.

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 terse fragments with no padding, and the core purpose is front-loaded. However, the second sentence (the endpoint path) adds little for an agent and the overall brevity edges toward under-specification given the absent return-value information.

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 simple read-only getter with a fully documented single parameter and annotations covering safety, the definition is minimal but workable. With no output schema, though, an agent gets no hint about what fields a customer record contains, which is the main remaining gap.

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 the single customer_id parameter is documented as a positive integer in the schema. The description adds no format, aliasing, or lookup guidance beyond that, so baseline 3 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 (get) and resource (one customer by id), and the sibling set makes the resource-based distinction obvious (get_order, get_product, list_customers). It is not tautological, but it stops short of explaining anything about the customer entity itself.

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?

"One customer by id" implies usage — call this when you have a customer_id — but there is no explicit guidance on when to prefer this over sapo_list_customers (e.g., when searching) or what to do if the id is unknown. Usage is inferable rather than stated.

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