rpg-mcp

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 discloses key behavioral traits: automatic application of ability modifier and proficiency bonus, and that it returns pass/fail if DC is provided. However, it doesn't cover other important aspects like error handling, response format, or whether it's a read-only or mutative operation.

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 appropriately sized with two sentences: a clear purpose statement and a helpful example. It's front-loaded with the core functionality. The example could be slightly more concise, but overall it avoids unnecessary verbosity.

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 tool with 7 parameters, no annotations, and no output schema, the description is adequate but has gaps. It covers the core purpose and some behavior, but doesn't fully address the complexity—missing details on return values, error cases, or how parameters like 'advantage' and 'disadvantage' interact.

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 high at 86%, so the baseline is 3. The description adds minimal value beyond the schema: it mentions 'characterId and skill' in the example but doesn't explain parameter interactions or provide additional context not already in the schema descriptions.

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 specific action ('Roll a skill check') and resource ('using character stats'), and distinguishes it from sibling tools like 'roll_ability_check' and 'roll_saving_throw' by specifying it's for skills with automatic modifier application. The example reinforces this distinction.

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 implied usage through the example ('for active character's Perception check'), suggesting it's for skill checks in role-playing contexts. However, it doesn't explicitly state when to use this tool versus alternatives like 'roll_ability_check' or 'dice_roll', nor does it mention prerequisites or exclusions.

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