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 it discloses nothing: no input format for "values", no output shape, no edge-case behavior (empty input, no shared prefix). For an unannotated tool this is a complete gap.

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?

It is short, but this is under-specification rather than conciseness. The duplicated "Common Prefix: Common Prefix" pattern wastes the one sentence it has on restating the name.

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?

No annotations, no output schema, and a placeholder parameter description leave the definition entirely dependent on a description that says nothing about input format, output, or behavior. Nothing an agent needs to call this correctly is present.

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 single parameter's schema description is the placeholder "Values to process", which conveys no meaning, and the description adds nothing on top of it. Nominal schema coverage is 100%, but the content is empty, so the agent learns nothing about whether values is a list, a delimited string, or how multiple values should be supplied.

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 a tautology: "Common Prefix: Common Prefix" simply restates the tool name and title without stating a verb, resource, or operation. An agent can infer from the name alone that it computes a common prefix, but the description itself contributes zero clarifying information and does not distinguish it from the sibling x402-common-suffix or x402-longest-common-substring.

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 conditions, no mention of alternatives such as x402-common-suffix. There is nothing telling an agent in which situations this tool is the right choice.

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