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

Annotations already indicate it is not read-only and not destructive. The description adds that results appear in Foundry chat and that actorId must be obtained from actor-list, providing useful behavioral context beyond what annotations supply.

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?

Two sentences with zero waste, front-loading the purpose and including essential usage and output details. No redundant or vague language.

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 simple two-parameter tool with no output schema, it covers the purpose, output location, and prerequisite. Everything an agent needs to invoke it correctly is present.

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 fully documents both parameters with descriptions and enums. The description adds a specific instruction for obtaining actorId (use actor-list), which goes beyond the schema and adds value.

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 specific verb (roll) and resource (D&D 5e skill check), clarifies it is for ability checks with proficiency, and mentions the output location (Foundry chat). This clearly distinguishes it from sibling tools like dnd5e-roll-ability and dnd5e-roll-save.

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?

Provides an explicit condition for use ('ability checks with proficiency') and a prerequisite ('Use actor-list first to find actorId'). While it doesn't name alternative tools directly, the context implies when not to use it, making it sufficiently clear.

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