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 by structured data. The description adds the underlying endpoint (GET /v1/services/{id}) and the shape of the returned detail, which is modest but real added context; no error or permission behavior is described.

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 with zero filler; the purpose and returned contents come first and the endpoint path is relegated to the tail. Every clause carries 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?

No output schema exists, but the description names the substantive fields returned (pricing, duration, option sections), which is enough for an agent to know a single-service lookup is the right call. It stops short of describing error behavior for an unknown id or any field-level structure.

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?

Only one parameter and schema description coverage is 100%, with the schema explaining that the id is 'the id field of a list result'. The description's 'by id' adds no format or sourcing information beyond that, so the 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 and resource ('One service by id') and enumerates the payload it returns (pricing, duration, option sections and their options), which is far more specific than a tautology. The contrast with the list_services sibling is implied by 'One service by id' rather than named outright, so it lands just short of the top band.

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 you call this when you already hold a service id and need full detail rather than a list. There is no explicit when-to-use/when-not statement and no prerequisite or alternative tool named.

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