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

The readOnly/destructive annotations already establish this as a safe read, so the description only needs to add context. It does add that include controls embedding of related records, but says nothing about errors, missing-record behavior, or what 'included' contains beyond what the schema states.

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, front-loaded with what is returned, followed by a compact endpoint identifier. No filler and nothing redundant.

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 single-record read with full annotation coverage, complete parameter docs, and a sibling list tool, this is nearly sufficient. The only real gap is that with no output schema, the shape of the returned applicant and its 'included' array is left unexplained.

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%, so the schema already documents both parameters, including the id source and the allowed include values. The description's mention of include adds no meaning beyond 'related records you ask for in include,' 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 and resource ('One interested applicant by UUID') and includes the underlying endpoint GET /interested-applicants/{id}. The singular 'One ... by UUID' distinguishes it from street_list_interested_applicants, but it does nothing to differentiate from the other applicant-type getters (lettings/sales) that populate the sibling list.

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 UUID' suggests it is the follow-up to the list tool, and the schema's id description names street_list_interested_applicants as the source. The description itself states no when-to-use or when-not conditions and names no alternative.

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