echo

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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly states the tool returns the input unchanged, implying a pure, side-effect-free operation. It does not discuss error behavior or formatting, but for an echo tool the core behavior is fully disclosed.

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?

A single, front-loaded sentence says exactly what the tool does and why it is useful. There is no redundancy or extraneous 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 one-parameter echo tool with an output schema present, the description covers the core behavior and intended use case adequately. No additional context about return values is needed because the behavior is fully implied by 'unchanged' and the schema.

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 schema has no property descriptions, so the description must compensate. The phrase 'Return *text* unchanged' implicitly references the 'text' parameter and conveys that it is echoed back, but it does not add explicit details like examples, constraints, or formatting. The single, self-explanatory parameter reduces the need for more.

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 uses a specific verb ('Return') and resource ('text'), clearly stating the behavior is to return the input unchanged. It also names the use case (round-trip testing), making it easy to distinguish from the sibling tool 'calculate'.

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 phrase 'useful for round-trip testing' gives an implied use case, but it does not explicitly state when to choose this tool over 'calculate' or when not to use it. There is minimal routing guidance, just enough to hint at its purpose.

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