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: not whether it is a read-only transform, what output format results (ordinal? comma-separated? words?), or any edge-case behavior. The description is entirely silent on 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 that brevity reflects under-specification rather than conciseness. The single four-word string merely echoes the tool name and the duplication ('Number Humanize: Number Humanize') earns nothing.

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, two unlabeled-ish parameters, and a tautological description, nothing an agent needs in order to call this tool correctly is present. The definition is wholly inadequate.

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 the baseline is 3 per the rubric. However, the two parameters ('value' and 'number') carry only generic descriptions ('Value to process' / 'Number to process'), and the tool description adds no clarification about which one to use or how they differ — the schema technically covers them but adds little real meaning.

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 'Number Humanize: Number Humanize' — a pure restatement of the tool name with no verb, no resource detail, and no indication of what 'humanize' means for a number. It provides zero differentiation from the many sibling numeric/formatting tools (e.g. x402-number-to-words, x402-format-thousands, x402-cron-humanize).

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, when-not-to-use, prerequisites, or alternative tools are mentioned. An agent has no basis to choose this over the numerous sibling formatting tools.

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