Echo

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

With no annotations provided, the description carries the burden of disclosing behavior. It explicitly notes 'No filesystem, network, or subprocess access,' which is a useful transparency statement about side effects. However, it does not describe validation details or error behavior, which is a minor gap.

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 that is perfectly front-loaded. Every word adds value, and the safety clarification is concise. No wasted space or redundancy.

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 simple tool with one fully documented parameter and an obvious return value, the description is complete. The safety constraint is included, making the context clear. No output schema is needed because the output is simply the input text.

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 coverage is 100% and the parameter description 'Text to return unchanged' is clear. The description adds the word 'validated' but does not elaborate on what validation entails. Overall, the schema does most of the heavy lifting, so a baseline of 3 is appropriate.

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 function: 'Return a validated text value unchanged.' It uses a specific verb ('return') and resource ('text value'), and distinguishes itself from the sibling tool by specifying it has no side effects or external access.

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?

Usage is implied by the description and name, but there is no explicit guidance on when to use this tool versus the sibling 'text_stats.' The description mentions safety constraints but does not provide context for when it is appropriate to choose echo over alternatives.

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