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

With no annotations, the description carries the full behavioral burden, yet it discloses nothing about output shape, error behavior, or edge cases (e.g., empty input, no common suffix). It only adds a pricing note ('5 free trial calls per signed wallet'), which is useful billing context but not behavioral.

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?

One front-loaded sentence delivers the core purpose with no filler. The trailing pricing tag is boilerplate but does not obscure the definition.

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 output schema, no annotations, and an undocumented parameter whose type appears to conflict with the description's 'array' wording. For an agent to call this correctly it needs more than what is provided.

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% and the single parameter 'values' is undocumented in the schema. The description calls it a 'values array' while the schema declares type string, creating ambiguity about the expected input format rather than clarifying it.

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 verb and resource: 'Finds the longest common suffix shared by all strings.' An agent can distinguish this from x402-common-prefix and x402-word-suffix from the description alone. It stops short of naming the alternative tool, so it is not a full 5.

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 on when to use this versus x402-common-prefix or other string-diff siblings, and no exclusions or prerequisites. Usage is only inferable from the name.

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