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

Annotations already declare readOnlyHint=true, so safety is covered structurally; the description adds genuinely new behavioral context by specifying the returned fields (contact details, addresses, customer group) and pinning the underlying REST call GET /customers/{customerId}. It stops short of noting error behavior for a missing id or auth/permission requirements.

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 compact sentences, front-loaded with what is returned and followed by the REST mapping. No filler or redundancy.

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 single-parameter read-only getter with no output schema, the description carries the return-value burden adequately by naming the returned field groups and the endpoint. Missing only edge-case guidance (not-found handling, whether the full customer object is returned).

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% for the single customer_id parameter, so the baseline is 3. The description adds only the phrase 'by id', which conveys no format, range, or source-of-truth information beyond what the schema already documents.

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 (a single customer by id) and enumerates the payload contents (contact details, addresses, customer group). It is clear on its own, but it never names or contrasts with the obvious sibling ecwid_search_customers, so an agent must infer the single-vs-list distinction.

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 by 'by id' — the agent can infer this is the direct-lookup path and search_customers is the discovery path, but neither the condition nor the alternative tool is stated. No prerequisites or exclusions are given.

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