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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it succeeds: 'Echoes the provided text back' fully describes the tool's behavior. There are no side effects, permissions, or hidden behaviors to disclose for this pure function.

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 sentence with no wasted words. The action is stated clearly and upfront, making it an example of efficient, appropriately sized writing.

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 tool this simple, with one fully documented parameter and no output schema, the description is complete. An agent has everything it needs to select and invoke the tool correctly.

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 provides a complete description of the single parameter ('Text to echo back'), so the tool description adds no additional semantic value beyond what is already structured. The baseline of 3 is appropriate because the schema fully documents the parameter.

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 a clear resource ('the provided text'), making the tool's function completely unambiguous. It is also easily distinguished from the siblings add and server_time, which perform entirely different operations.

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 the siblings, nor does it mention any exclusions or alternative conditions. However, the intended use is strongly implied by the tool's simple and self-explanatory purpose.

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