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 clearly states the core behavior: the input message is returned to the caller. Echoing is inherently a non-destructive, read-only operation, so there are no hidden side effects or safety concerns to disclose.

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?

One short sentence that front-loads the verb and object with zero waste. Every word earns its place, and no redundant phrasing or repetition exists.

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 single-parameter echo tool with an output schema present, the description is complete. An agent can invoke it correctly with no additional information, and the return value is covered by the output schema rather than needing description-level detail.

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 description coverage is 0%, so the description must compensate. It refers to the 'input message,' which maps directly to the single required message parameter, but it adds no constraints, formatting rules, or examples beyond what the schema's title and type already convey.

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 (Echo) and resource (the input message), clearly stating that the tool returns the same message back to the caller. It is unambiguous and inherently distinct from the sibling tools, none of which perform an echo operation.

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 does not explicitly state when to use this tool versus alternatives, nor does it mention exclusions or prerequisites. However, for a trivial echo operation, the intended usage is implied by the description itself: an agent needing to mirror a message would select this tool.

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