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: no return format (rounded number? string? array?), no edge-case handling (trailing zeros, negative values, scientific notation), no determinism or side-effect information.

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 only because it is empty: the single phrase duplicates the tool name twice and carries no information. Brevity here reflects under-specification rather than efficient, front-loaded content.

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 two-parameter math utility with no annotations and no output schema, the definition supplies no semantics, no example, and no behavioral detail, leaving the agent unable to call the tool correctly.

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 nominally 100%, but the schema descriptions are content-free placeholders ("Value to process", "Digits to process") that do not say whether 'value' is a numeric string and whether 'digits' is a count, a digit list, or a mode. The description adds nothing to resolve this, and the string typing of 'digits' is left unexplained.

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 "Significant Digits: Significant Digits", a pure tautology that restates the tool name without a verb or any statement of what operation is performed. It gives no way to distinguish this tool from near-identical siblings such as x402-sig-figs, x402-format-significant, x402-number-precision, or x402-round-to.

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 indication of when to use this tool, when not to, or which sibling to prefer for related rounding/precision tasks. The agent is given no routing information whatsoever.

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