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

No annotations are provided, so the description carries the full behavioral burden and delivers nothing: no indication of whether the operation is read-only, what the output shape is, or how matching is performed. This is a null disclosure for a tool that could be expected to have non-obvious matching semantics.

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?

Technically short, but it is pure repetition of the title with zero informational content — under-specification disguised as brevity, not conciseness.

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?

With no annotations, no output schema, two ambiguous parameters, and a heavily populated sibling namespace, the description would need to do substantial work. It does none, leaving the agent unable to invoke the tool correctly or route to the right alternative.

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 nominally 100%, but the two parameter descriptions are content-free boilerplate ('Text to process', 'Input to process'), and the description adds nothing. Critically, it does not explain the intended difference between the 'text' and 'input' parameters, which is exactly where an agent would need help.

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 is the literal title repeated twice ('Words Containing: Words Containing'), which is a tautology restating the tool name. It never states what the tool actually does to the input text or what a 'word containing' result looks like, so an agent cannot distinguish it from siblings like x402-word-prefix or x402-contains-any.

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 when-to-use guidance, no prerequisites, and no mention of any alternative tool. The agent is left to guess entirely from the name.

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