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

No annotations are provided, so the description carries the full burden of behavioral disclosure, and it discloses nothing — not whether this is a read-only check, whether it hits an external registry, what it returns, or what inputs are required. All three parameters are also optional, so the description gives no clue about default behavior.

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 not concise — there is no substantive content to be concise about. This is under-specification rather than efficient brevity, scoring similarly to the tautological 'Process' example.

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 three-parameter tool with no annotations, no output schema, and no parameter documentation, the description is completely inadequate. An agent has no basis to invoke this correctly versus the many sibling validation/formatting tools.

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 100%, so per the baseline the schema is nominally responsible for the parameters. However, the schema text is placeholder boilerplate ('Value to process', 'Number to process', 'Routing to process'), and the description adds nothing to disambiguate why three overlapping string parameters exist. Baseline 3 applies, but the value added is nil.

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 'Routing Number: Routing Number', which merely repeats the tool name twice. It states no verb and no action, so an agent cannot tell whether this validates, looks up, generates, or formats a routing number — especially with a sibling named x402-is-routing-number sitting next to it.

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 guidance of any kind: no when-to-use, no when-not-to-use, and no mention of any alternative tool. The agent must guess the trigger conditions 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.