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

With no annotations and a tautological description, there is zero disclosure of behavior. It does not state that this is a pure computation, whether it is read-only, what happens with invalid inputs, or what units are involved.

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 redundant restatement of the title with no informative content. It is concise only in the sense of being empty, not front-loaded with useful 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?

Missing everything an agent needs: no explanation of Heron's formula, no indication of input format (side lengths as strings?), no output description, and no relation to sibling geometry tools. Completely inadequate.

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?

Although schema description coverage is technically 100%, the schema descriptions are placeholders ("A to process", "B to process", "C to process") that provide no meaning. The description adds nothing to clarify that a, b, and c are the triangle side lengths.

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 "Triangle Heron: Triangle Heron" is a tautology that merely restates the tool name with no verb, resource, or scope. It gives no indication of what computation is performed (Heron's formula for triangle area from three sides) or what the output is.

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 guidance whatsoever on when to use this tool, what inputs are expected, or how it differs from siblings like x402-triangle-area or x402-triangle-perimeter. The agent has no basis for selection.

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