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

With no annotations, the description carries the full burden. It does disclose the output shape (formatted string plus line count) and hints at a payment/wallet-gated trial, which is genuine behavioral context. It says nothing about how malformed XML is handled, whether input is validated, or what errors look like.

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?

A single front-loaded sentence that describes indent width, output, and cost in short order. The free-trial emoji clause is promotional noise, but it does not bloat the definition significantly.

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 transformation tool with four undocumented aliased parameters, no annotations, and no output schema, the description should resolve the parameter ambiguity and at least note failure behavior. As written, an agent cannot reliably construct a correct call from the definition alone.

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% across four string parameters (xml, data, text, input) that appear to be aliases, and the description explains none of them. It implies XML text is the input but never tells the agent which of the four fields to populate, so the caller is left guessing.

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 action and resource ('Indents XML') with concrete behavior ('two spaces per nesting level') and return content ('formatted string plus its line count'). This separates it from validators and converters like x402-xml-validate or x402-xml-to-json, though it never names a sibling 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?

There is no when-to-use guidance, no statement of when this is preferable to x402-json-pretty or other XML siblings, and no mention of prerequisites. The only contextual sentence is a pricing note ('5 free trial calls per signed wallet'), 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.