Echo

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

The description does not contradict annotations (readOnlyHint: true). It adds the context that it's a smoke-test tool, implying no side effects. However, it doesn't provide additional behavioral details beyond what annotations already convey.

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, concise sentence with no unnecessary words. It efficiently conveys 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?

For a simple echo tool with output schema and annotations, the description is mostly complete. However, it lacks guidance on usage or behavioral nuances, but given the tool's simplicity, it is adequate.

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 has 100% coverage with a description for the 'message' parameter. The description adds no extra meaning beyond 'Message to echo.' Baseline 3 is appropriate as schema already 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 clearly states it's a 'Development smoke-test tool', indicating its purpose for testing. It is short but effectively communicates what the tool does. While it doesn't differentiate from siblings, the siblings are diverse, so confusion is unlikely.

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 implies it's for testing purposes only (smoke-test), but does not explicitly state when to use it versus alternatives or provide exclusions. Usage context is minimal.

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