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

With no annotations, the description effectively discloses the echo behavior and size constraints. It is clear that the tool is read-only and returns the input. A slightly higher score would require explicit mention of no side effects or authentication needs.

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 efficient and front-loaded with the core purpose. Every word is necessary, and there is no redundant information.

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 one parameter, the description covers purpose and size limits. It does not explain what 'echo' means in detail, but given the presence of an output schema, that is acceptable. Minor improvement could clarify the echo behavior.

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 description does not reference the only parameter, json_data. With 0% schema description coverage, the description should provide additional context but fails to do so. The parameter name is self-explanatory, but the description adds no semantic value.

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 receives JSON and returns it as echo, identifying the core purpose. However, it lacks an explicit statement that it is a testing/debugging tool, and sibling differentiation is implied rather than explicit.

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 size limits for Free vs Premium tiers, which gives context, but does not explicitly guide when to use json_echo over text_echo. The differentiation is implied by the input type.

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