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

Goes well beyond the annotations: explains the two-step email confirmation with a 24-hour window, that nothing reaches Dario until the user clicks, response time expectation, idempotent repeat behavior, rate limit (5 per email per day) and rejection of throwaway addresses. It substantiates the idempotentHint rather than merely restating it.

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-loads purpose, then the precondition, then the mechanics, then limits. Every sentence carries information an agent would otherwise have to guess; no filler.

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?

With 9 parameters, no output schema and openWorldHint, the description covers the full lifecycle (what is sent, when, by whom, limits, what comes back). The return payload is described in prose in lieu of an output schema.

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%, so the baseline is 3, but the description adds real meaning: userConfirmed is a hard gate tied to a user-visible confirmation step, name/email must be the user's own, and the message is shown to Dario verbatim. Phone, locale, product and URL params are left entirely to 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?

Opens with a specific verb and resource: 'Starts a real contact request for the user.' It is immediately distinguishable from get_quote, list_products and list_work, which are read/lookup siblings, and the title reinforces the intent.

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?

'Call ONLY after the user has seen exactly what will be sent and said yes (set userConfirmed true)' is an explicit precondition, and 'use their own name and email' is an explicit constraint. The message parameter also points to get_quote as the source of details to include.

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