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

There are no annotations, so the description must carry the burden of exposing behavior. It clearly states the tool's only effect: echoing back the provided input. This is fully transparent for a simple stateless operation, though it does not explicitly confirm the absence of side effects or storage; for an echo tool this is minimal and acceptable.

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, clear sentence that directly states functionality. There is no fluff, and it occupies the minimal space needed to convey the tool's purpose.

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?

The tool has one straightforward parameter, no output schema, and no side effects. The description fully covers what an agent needs to know to call and interpret the result. Nothing important is missing.

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 100% and the parameter 'text' is already described as 'Text to echo back'. The description adds no additional semantic detail beyond the schema, which is adequate. There is no need for further clarification because the parameter meaning is self-explanatory.

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 ('echoes') and resource ('provided text') with a clear outcome: the text is returned to the caller. It is immediately distinguishable from sibling tools 'add' and 'server_time' because those imply arithmetic and time retrieval, while this is a direct passthrough 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?

No guidance is provided about when to use this tool versus alternatives like 'add' or 'server_time'. The description is purely functional and does not mention any use cases, exclusions, or selection criteria, leaving the agent to infer based on the name alone.

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