cr_scale

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

With no annotations provided, the description carries the behavioral burden and does so well by stating exactly what the tool returns: proficiency bonus, expected AC, HP range, attack bonus, DPR range, and save DC. It also implies a read-only lookup through the phrase 'Look up'. It does not mention edge cases like invalid CR values, but for a pure table lookup the disclosed behavior is largely sufficient.

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 description is two sentences with no filler. The first sentence states the action and outputs, and the second supplies practical use cases. Every clause earns its place and the most important information is front-loaded.

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 single-parameter, no-output-schema lookup tool, the description is complete: it names the input domain, lists all returned fields, and gives usage context. It could be slightly stronger by distinguishing itself from cr_calculate, but nothing essential for correct invocation is missing.

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%: the cr parameter already includes valid values and the accepted format. The description only refers to 'a given Challenge Rating' and 'target CR', adding no substantive meaning beyond the schema, so the baseline 3 is appropriate.

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 uses a specific verb ('Look up') and a clear resource ('expected stat ranges for a given Challenge Rating from the DMG reference table'). It also lists concrete return values, so the tool's function is unmistakable. It does not explicitly contrast with siblings like cr_calculate, but the lookup-oriented wording provides reasonable differentiation.

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?

The description gives explicit use cases: scaling a homebrew monster up or down to a target CR, and checking whether a monster's stats fit its CR. It does not state exclusions or compare directly with alternatives such as cr_calculate, but the context is clear enough for an agent to know when to invoke it.

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