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

Annotations are sparse (no meaningful hints beyond non-readonly), so the description carries the burden. It usefully discloses that a person reads every message and that replies are not instant, and it promises a receipt ID. This adds behavioral context beyond the schema without contradicting annotations.

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 no filler. The core action and message kinds are front-loaded, followed by the key output (receipt ID) and the important human-review latency caveat.

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 contact form with full schema coverage and an output schema, the description covers the essential behavior: what to send, what you get back, and the non-instant nature of replies. The only notable gap is explicit guidance on when to choose a sibling tool instead.

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 all four parameters thoroughly. The description repeats the enum values in prose but does not add new semantic detail about message formats, email behavior, or acknowledgment requirements.

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 states a specific action ('send') and resource ('a message'), and enumerates the accepted kinds: question, scoping, partnership, or press. This clearly differentiates it from siblings like check_status and submit_claim, which serve different purposes.

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 implies when to use the tool—for general questions and partnership/press outreach—but never explicitly contrasts it with sibling tools. It does not say 'for claims, use submit_claim' or 'to check progress, use check_status', leaving the routing partly to inference.

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