DM20 Protocol

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

No annotations are provided, so the description carries the full burden. It adds useful context about rulebook manager priority, which isn't obvious from the schema. However, it lacks details on potential errors (e.g., if the spell isn't found), response format, or any rate limits or permissions needed, leaving behavioral gaps.

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 front-loaded with the core purpose in the first sentence, followed by contextual details. Both sentences are necessary and add value without redundancy. It's efficiently structured and appropriately sized for the tool's complexity.

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 read-only tool with one parameter and no output schema, the description covers the basic purpose and usage context adequately. However, without annotations or output schema, it lacks details on return values, error handling, or dependencies, making it incomplete for full agent understanding.

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 input schema has 100% description coverage, with the 'name' parameter well-documented. The description doesn't add any parameter-specific information beyond what the schema provides, such as examples or constraints. Given the high schema coverage, a baseline score of 3 is appropriate, as the schema does the heavy lifting.

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's purpose: 'Get spell details from loaded rulebooks.' It specifies the verb ('Get') and resource ('spell details'), making it easy to understand. However, it doesn't explicitly differentiate from sibling tools like 'get_class_info' or 'get_monster_info', which follow a similar pattern, so it doesn't fully distinguish 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?

The description provides clear context on when to use it: 'Works without a campaign loaded (uses global rulebook manager). When a campaign is active, its rulebook manager takes priority.' This explains the tool's behavior in different scenarios. However, it doesn't mention alternatives or exclusions, such as when other tools might be more appropriate.

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