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

With no annotations, the description carries the full burden and does so: it discloses validation behaviour, the returned summary/consent line/confirmation token, the requirement that the recipient click an email link before any provider sees the enquiry, and the exact consent wording shown at step 1. The no-third-party-sharing and email-notification side effects are explicit.

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?

Front-loaded with the critical scoping statement ('NOT a purchase') and cleanly segmented into Step 1/Step 2. The quoted consent sentence is fairly long and repeated in the schema, so there is minor redundancy, but every clause carries operational meaning.

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 mutation-style, two-phase tool with no output schema and a nested answers object, the description supplies what the return of each call contains, the gating conditions, and the consent contract. Nothing an agent needs to execute the flow correctly is missing.

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 coverage is 100%, but the description still adds real meaning: 'answers' is keyed by field key obtained from enquiry_fields, 'consent' must be true only after the person has read the quoted consent text, and 'confirmation' is the token returned by step 1 after approval. This explains the cross-call relationship between the two invocations, which the schema cannot.

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 (submits) and resource (enquiry to Bank Code Lookup) and immediately draws the boundary that it is NOT a purchase or guaranteed quote. It references the sibling enquiry_fields as the source of field keys, so an agent can distinguish it from the other enquiry_* tools without opening schemas.

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?

Gives an explicit two-step protocol: step 1 validates and returns a summary/consent/token, step 2 is only called if the person agrees, with the exact parameter set for each call. It also names the prerequisite field source (enquiry_fields) and the human-approval condition, leaving nothing to inference.

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