echo

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions that the echoed message may include 'any configured prefix,' which adds some context about potential modifications. However, it lacks details on side effects, error handling, rate limits, or authentication needs, which are important for a tool with no annotation coverage.

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 appropriately sized and front-loaded, with the core purpose stated first, followed by brief sections for arguments and returns. Every sentence earns its place, and there is no wasted verbiage, making it efficient and easy to parse.

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?

Given the tool's simplicity (one parameter, no siblings, no annotations) and the presence of an output schema, the description is reasonably complete. It explains the purpose, parameter, and return behavior, though it could benefit from more behavioral context. The output schema likely covers return values, reducing the need for detailed return explanations in the description.

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 description coverage is 0%, but the description compensates by explaining the single parameter: 'message: The message to echo.' This adds clear meaning beyond the bare schema. Since there's only one parameter and it's well-described, the score is high, though not perfect due to the lack of details on format or constraints.

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's purpose: 'Echo a message back to the client.' It specifies the verb ('echo') and resource ('message'), making it easy to understand what the tool does. However, since there are no sibling tools, it doesn't need to differentiate from alternatives, which prevents a perfect score of 5.

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 provides no guidance on when to use this tool versus alternatives or in what context it should be applied. It simply states what the tool does without any usage instructions, prerequisites, or exclusions, leaving the agent with minimal operational context.

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