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 and mutability are covered. The description adds that requested relations are embedded under 'included', which is useful behavioral context, but it omits error behavior (e.g., 404) and any pagination or size considerations for the include list.

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 sentences with the key point (single applicant by UUID) front-loaded and the include behavior immediately after. The trailing 'GET /sales-applicants/{id}' is mildly redundant with the schema but harmless.

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 tool with full annotations and a fully documented two-parameter schema, the description covers the essentials: what is fetched and how relations are embedded. It could do more on failure modes or the shape of the response, but with no output schema and rich annotations the gap is modest.

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 schema already enumerates all nine include values and explains that sales_applicant_id comes from street_list_sales_applicants. The description only restates that 'include' controls embedded related records, adding no syntax or format detail beyond the schema.

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 names a specific verb and resource ('One sales applicant by UUID') and scopes it to a single record, which implicitly contrasts with the sibling list tool street_list_sales_applicants. It stops short of naming that sibling explicitly, so an agent must infer the 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?

The description makes clear this is a single-record fetch keyed by UUID and that related data comes through 'include', which implies the lookup-after-list workflow. It does not state when to prefer this over street_list_sales_applicants or what happens if the UUID is unknown.

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