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

Adds real context beyond the annotations: a cryptographic source, inclusive bounds, a metered cost model ($0.01/call, first 25 free, failed calls free) and that repeats are billed again, which reinforces idempotentHint=false. The "reads or computes only and changes nothing" clause largely restates readOnlyHint, so it earns no extra credit.

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?

Purpose and range semantics are front-loaded in the opening clause, and the pricing sentence carries genuinely useful agent-facing information. The dangling "Example: min=1." is a truncated fragment that wastes a slot without illustrating anything.

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 four-parameter, all-optional, non-destructive compute tool with a fully described schema, this covers range semantics, uniqueness, randomness quality and cost. The only real gap is the shape of the return value when count > 1, which no output schema fills in.

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?

With 100% schema coverage the baseline is 3, and the description goes further by clarifying that ranges are inclusive and that `unique` means "all different" — details the schema does not spell out. It still does not describe what `count` returns (single value vs array).

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 concrete verb and resource: generating one or more random whole numbers within an inclusive range, from a cryptographic source. The resource is clearly narrower than random_pick or random_shuffle, but siblings are never named, so the agent must infer the boundary itself.

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?

"Use for draws, sampling and games" gives a clear positive context for when this tool applies. It stops short of exclusions or pointing at alternatives like random_pick (list-based) or dice, which would have made routing unambiguous.

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