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

Annotations only flag this as a non-read-only, open-world, non-destructive write. The description adds genuinely useful behavioral context beyond that: the action sends an external email, is capped at three recipients, and mandates explicit user confirmation before proceeding. It does not describe delivery failure behavior or whether the email can be recalled, so it falls short of a 5.

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 tight sentences with the action front-loaded and the confirmation requirement immediately after; every clause earns its place with 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?

An output schema exists, so return values need not be explained, and the safety profile is covered by annotations plus the stated confirmation gate. The one omission is any reference to the preview/options siblings that an agent would likely need before sending.

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%, including the 3-recipient cap and the meaning of 'confirmed', so the schema already carries the parameter burden. The description repeats the recipient limit but adds no new syntax, format, or selection semantics beyond what the schema states.

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 concrete verb and resource ('Emails ... vehicle, setup, and session details') plus the scope constraint of up to three recipients, so the agent knows exactly what the tool produces. It does not, however, distinguish itself from the closely related siblings preview_share_build or get_share_build_options.

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 supplies one important precondition — 'Explicit user confirmation is required' — which is implied usage guidance for a send action. It never states when to call this versus preview_share_build (e.g. preview first, then send) or get_share_build_options, leaving the agent to infer the ordering.

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