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. It states a pure transformation but omits everything about behavior: accepted input syntax, handling of edge cases (zero, negatives, very large/small numbers), and whether output is a string or number. For a param-bearing formatter with zero annotation coverage this is a clear 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?

One tight sentence with zero waste, front-loaded with the verb and format. It is appropriately sized, though the extreme brevity is what leaves the other gaps unfilled rather than excess text hurting it.

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, and only bare schema parameter descriptions, the description does almost none of the work required for a 2-parameter transformation tool. It never describes input format, output format, or the semantics of 'decimals', leaving the agent to guess at calling conventions.

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% (both 'value' and 'decimals'), so the baseline is 3. However, the schema descriptions are bare ('Value to process', 'Decimals to process') and the tool description adds nothing—critically, it never clarifies what 'decimals' means for scientific notation (mantissa precision vs. exponent decimals), which is the one thing the description should disambiguate.

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 + resource (format a number) plus the exact output format (scientific notation). This cleanly distinguishes it from the many sibling formatters like x402-format-fixed, x402-format-decimal, and x402-scientific-notation without the agent needing to open any schema.

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 when-to-use guidance, no mention of prerequisites, and no routing to alternatives. Given the enormous sibling set of formatters, an explicit exclusion (e.g. 'for engineering notation use x402-engineering-notation') would be valuable but is absent.

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