create_email_test

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

Discloses key behaviors: idempotent POST, creates a fresh session each call (no modification of prior sessions), returns an address valid for 60 minutes, language defaults to en, and no auth required. With no annotations, the description fully covers behavioral traits.

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 essential: main purpose, return values and idempotency, then usage instructions. No redundant words, well-structured, and front-loaded with key info.

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 one optional parameter and no output schema, the description covers creation, return values, validity, usage steps, idempotency, and language variants. It is fully self-contained and clear.

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% with one parameter already described. The description adds 'controls result text' for language, providing context beyond the schema's 'Result language'. This extra meaning justifies a score above baseline.

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 clearly states it creates a new inbound email-test session, returning a unique single-use email address and testId. It distinguishes itself from sibling tools like get_email_test and poll_email_test by mentioning them.

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?

Explicitly explains when to use: debugging outbound mail's SPF/DKIM/DMARC/headers/spam triggers, and that after sending a mail to the returned address, one should call poll_email_test. Does not explicitly state when not to use, but provides clear workflow guidance.

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