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

The readOnlyHint annotation already indicates this is a safe, non-destructive operation. The description adds that the tool simply returns the input unchanged, which is consistent with the annotation. However, 'Replace with real tools' creates ambiguity about whether this tool is a functional stub, and no additional behavioral context such as output formatting is provided.

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 first sentence is concise and front-loaded: 'Return the text you pass in.' The second sentence, 'Replace with real tools,' is a developer-facing placeholder instruction that does not help an agent invoke the tool correctly and should be removed or replaced.

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 trivial echo operation with a read-only annotation and a single obvious parameter, the essential information is present. However, the placeholder comment undermines certainty about whether the tool is production-ready, and there is no explanation of typical use cases or expected behavior beyond the basic echo.

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 for the undocumented 'text' parameter. It does map the parameter to behavior by saying 'the text you pass in' is returned, but it adds no constraints, examples, or formatting details. For a single trivial string parameter this is minimally adequate, though not comprehensive.

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 clear, specific action: 'Return the text you pass in.' This identifies the tool as an echo/reflection tool and distinguishes it from generic processing tools. The appended 'Replace with real tools' is a placeholder note that slightly weakens the clarity, so it is not a perfect 5.

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 provides no guidance about when to use this tool or when an alternative would be preferable. There are no sibling tools listed, and the placeholder phrase 'Replace with real tools' does not clarify usage context or intended scenarios.

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