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

No annotations are provided, so the description carries the full burden. The single sentence fully discloses the tool's behavior — it returns the input text unchanged. For a tool with zero side effects, authentication needs, or hidden behavior, this is complete disclosure, and the phrase 'back to the caller' adds a subtle but useful clarification about the return value.

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?

A single sentence with zero informational waste. Every word serves the purpose of stating what the tool does, and no irrelevant detail is included.

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?

Complete for what this tool is. One parameter fully documented in the schema, no output schema concerns, and the behavior is fully described. There is no complexity an agent would need additional context to handle.

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% — the schema already describes 'text' as 'Text to echo back'. The description adds no additional parameter meaning beyond the schema's coverage, which lands at the baseline 3 for full schema coverage.

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 object ('the provided text') plus a clear outcome ('back to the caller'). This is unambiguous and naturally distinguishes the tool from its siblings (add, server_time) without naming them.

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 explicit when-to-use or when-not-to-use guidance, and no alternatives are named. However, for a trivially simple tool, usage is strongly implied by the purpose — use it when you want text returned unchanged. The guidance is barely needed, but it's absent, so 'implied usage' applies.

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