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

Annotations already indicate this is a write operation (readOnlyHint=false, idempotentHint=false), and the description adds meaningful behavioral context: it emails multiple parties, returns a WhatsApp link and reference, and fails with key_required if no key is present. It does not contradict annotations. It could go further by describing whether the operation is reversible or what happens on duplicate calls, but the disclosed side effects are substantial.

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?

Three sentences, each carrying distinct information: what the tool does, when to call it, and what to avoid plus the key failure mode. The most important operational constraints are front-loaded. No filler or repetition of schema fields.

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 tool with 8 parameters and an output schema, the description covers the essential workflow: prerequisites, side effects, the health-detail prohibition, and the key requirement. It doesn't spell out the exact return structure, but an output schema exists, so that burden is reduced. The only notable gap is that it doesn't explicitly say what happens if the person hasn't given consent, though that is strongly implied by 'only call it once they have said they want to be contacted'.

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 only 25%, so the description must compensate. It does: it clarifies that name and a phone/email are prerequisites, that the note must never contain health details, and that option_id is 'the plan they want to talk about'. It doesn't explain every parameter (e.g., age, gender, preferred_contact), but the most safety-critical and workflow-critical parameters are covered.

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 uses a specific verb ('pass the person to a licensed adviser') and names the concrete side effects: saves the enquiry, emails the shortlist, emails the adviser, returns a WhatsApp link and a reference. It clearly distinguishes this from sibling tools like find_plans or compare_plans, which are about plan discovery rather than handing off a lead.

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 gives explicit preconditions: only call once the person has given a name and a phone number or email and has said they want to be contacted. It also states a hard exclusion ('Never put a health detail in the note') and explains the key requirement. This is strong when-to-use guidance that an agent can act on without ambiguity.

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