Read messages for a test email address

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

With no annotations, the description carries the transparency burden. It adds the behavioral nuance of 'received so far', indicating a non-waiting snapshot of current messages. It also discloses the prerequisite of an address created by create_test_email, but does not mention return format or error handling.

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?

The description is a single, front-loaded sentence that efficiently conveys purpose, scope, and prerequisite. There is no wasted wording.

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 one-parameter tool, the description is nearly complete: it specifies what is returned (messages), the source (address), and the condition ('received so far'). It lacks explicit details about the return message format, but the absence is acceptable given the tool's straightforward nature.

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 input schema already has 100% description coverage for the 'address' parameter, so the baseline is 3. The tool description primarily echoes the schema's description, reinforcing the link to create_test_email but adding little extra semantic meaning.

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 the tool retrieves messages for a test email address, using the verb 'Get' and specifying the resource 'messages'. It distinguishes itself from siblings like wait_for_test_sms and list_services by referencing the test email address.

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 the tool is used after create_test_email, as it specifies 'created with create_test_email'. It clearly indicates the context of use, though it does not explicitly name alternative tools or state when not to use it.

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