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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals the operation and the [REDACTED] token but omits critical matching semantics for a redaction tool: case sensitivity, word-boundary vs substring matching, and whether all occurrences are replaced. An agent cannot predict how input like 'Python' interacts with a word list containing 'python'.

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 sentences with no filler: the first sentence front-loads the operation and output format, the second delivers input instructions. Every word earns its place, and the structure logically flows from what it does to how to invoke it.

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 text transformation with an empty schema and no annotations, this description covers the core operation and both inputs, which is adequate. The gaps are match semantics (case sensitivity, word boundaries), the return format, and behavior on repeated occurrences — meaningful unknowns for a redaction tool that an agent would only discover by trial and error.

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 schema is empty (0 parameters), yet the description compensates by naming the exact inputs: 'text' and a 'words array (or comma list)'. This is genuine added value since the schema provides nothing, and it clarifies the accepted formats. It stops short of specifying precise types or constraints, but for the baseline-4 case of 0 parameters this is strong coverage.

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 states a concrete action with a specific verb and resource: 'Replace specified words in text with [REDACTED]'. It goes beyond the name by naming the exact replacement token, so an agent knows what output format to expect. However, it does not distinguish itself from sibling tools like x402-mask or x402-replace-all, which could plausibly overlap in purpose.

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 is given on when to choose this tool over alternatives such as x402-mask, x402-replace-all, or x402-template-replace. The description tells the agent what inputs to provide but never establishes usage context or exclusions, leaving tool selection to inference.

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