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

No annotations are provided, so the description should disclose behavioral traits. It only states 'Returns: {probability}' without specifying format (e.g., decimal, fraction), accuracy, or performance considerations. This is insufficient for a calculation tool with potential combinatorial complexity.

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 concise—two sentences no fluff. The first sentence immediately states the action and scope, the second gives return format. It wastes no words and is well-structured.

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?

The tool has an output schema (true), so description needn't detail return structure, but it only says 'Returns: {probability}'. For a probability calculator, this is adequate but could specify whether it's a number between 0 and 1 or a percentage. Contextual completeness is average.

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?

All four parameters have descriptions in the input schema (100% coverage). The description adds no new information beyond the schema. It repeats the comparison types, which are already defined. Baseline 3 is appropriate as schema carries the burden.

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 clearly states the tool calculates dice roll probability for exact, minimum, or maximum targets. The verb 'calculate' and resource 'dice roll probability' are specific. The mention of 'Returns: {probability}' clarifies output. It distinguishes from hundreds of siblings by focusing on dice probability.

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 provides minimal guidance. It only suggests seeing list_bundles for related calculators but does not specify when to use this tool versus alternatives, nor does it mention any prerequisites or limitations.

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