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

With no annotations, the description carries the full burden and discloses important lifecycle behavior: the address expires after 10 minutes without a wait_for_report call and accepts only one message. It still omits some operational details such as whether wait_for_report extends the expiration or what happens after expiry.

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 short sentences, front-loaded with the purpose and followed by the required workflow and lifecycle constraints. Every sentence contributes useful information.

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 zero-parameter setup tool with no output schema, the description is complete enough: it explains what the tool creates, how to use the resulting address, what values are returned, and the expiration/message constraints.

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?

The tool has zero input parameters, so the baseline is 4. The description mentions returned token and key but correctly does not invent parameter semantics for a no-argument tool.

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 verb and resource: 'Create a temporary echo.email address.' It also distinguishes the tool from its siblings by explaining that it is the setup step before calling wait_for_report.

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?

It gives a clear procedural usage guideline: send one email from the system under test, then call wait_for_report with the returned token and key. It does not state when not to use the tool or name any alternative beyond the next workflow step.

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