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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it contributes nothing: no mention of what the tool computes or returns, no assumed distribution parameters, no side-effect or safety profile. The agent learns nothing beyond the tool's name.

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?

The four-word description is short, but this is under-specification rather than conciseness — there is no informative content to front-load. As in the 'Process' calibration example, brevity that omits all semantic content is scored as incomplete, not efficient.

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?

Completely inadequate for the context. With no annotations and no output schema, the description was the agent's only information source, yet it fails to define the distribution parameters, output semantics, or how this differs from the nearly identical x402-standard-normal-cdf sibling. An agent cannot confidently select or invoke this tool.

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?

The schema has 0 parameters, which normally earns a baseline of 4 since there is nothing to document. However, a 'normal CDF' with no declared inputs is intrinsically ambiguous — the description does not clarify whether the tool assumes a standard normal (mean=0, sd=1), reads implicit context, or duplicates x402-standard-normal-cdf entirely. That unresolved ambiguity justifies marking down from the baseline.

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 "Normal Cdf: Normal Cdf" is a pure tautology — it restates the tool name with zero elaboration. It uses no meaningful verb, defines no resource or scope, and provides nothing to distinguish it from near-identical siblings like x402-standard-normal-cdf, x402-normal-pdf, or x402-normal-quantile.

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 usage guidance of any kind. The sibling set contains extremely close alternatives (x402-standard-normal-cdf, x402-normal-pdf, x402-normal-quantile, x402-standard-scale), yet the description never states when this tool should be selected or mentions any alternative. An agent has no basis for choosing it.

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