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

With no annotations, the description carries the full behavioral burden. It discloses the payment/auth model ('5 free trial calls per signed wallet'), which is genuinely useful context, but it says nothing about whether the tool is pure computation, how inputs combine, or what the result contains.

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 definition is two short elements with the core purpose front-loaded. The emoji and trial-call tagline are marketing filler but do not obscure the meaning.

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 three-parameter tool with no annotations, no output schema, and no parameter documentation, the description leaves too much unexplained. An agent cannot infer from it alone how to split a bill versus compute a tip percentage.

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 three parameters (amount, people, percent) are entirely undocumented. The description only implies 'tip' and 'bill split' semantics without explaining types, mutual exclusivity, or how percent and amount interact.

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 names a specific verb and resource: 'Calculate tips and bill splits.' An agent can tell it is a calculator-style tool. However, it does not distinguish itself from the sibling x402-tip-split, which appears to cover overlapping ground.

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?

There is no guidance on when to use this tool instead of alternatives such as x402-tip-split, x402-percent, or x402-percent-of. The only contextual note is the free-trial pricing line, which is not usage guidance.

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