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

With no annotations, the description carries the full burden. It does add real behavioral context by disclosing the monetization model ('5 free trial calls per signed wallet'), which tells the agent about access requirements. However, it says nothing about return format, precision/rounding, or error behavior for a computation tool.

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?

Two short sentences, purpose first, inputs second, no wasted filler. The pricing note is appended cleanly at the end rather than interrupting the core instruction.

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 numeric tool with zero annotations, no output schema, 0% schema coverage, and no required-field marking, the description should specify units and the C1V1=C2V2 relationship. As written, an agent can guess the intent but cannot confidently format inputs or anticipate the response.

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 coverage is 0% and all three parameters are untyped strings. The description merely repeats the parameter names ('initialConcentration, initialVolume, and finalVolume') without units, expected number format, or which value is the output. It does not compensate for the total absence of schema documentation.

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?

States a specific verb and resource: 'Calculate the final concentration after dilution.' An agent can distinguish it from related siblings like x402-concentration or x402-molarity by the dilution framing, though no sibling is named explicitly.

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 only says which values to supply, which is input listing rather than when-to-use guidance. It gives no conditions, no exclusions, and no pointer to alternatives such as x402-concentration for non-dilution concentration problems.

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