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 describes the core behavior (d20 roll with specific outcomes) but doesn't mention side effects like updating character state, permission requirements, or error conditions. For a mutation tool with zero annotation coverage, this leaves significant 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 a single, information-dense sentence with zero waste. It front-loads the purpose and includes all essential outcome rules without unnecessary words.

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 mutation tool with no annotations and no output schema, the description covers the basic purpose and rules adequately. However, it lacks information about what the tool returns, how it affects game state beyond the described outcomes, and error handling. Given the complexity and lack of structured data, it should do more to be complete.

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 67% (2 of 3 parameters have descriptions). The description doesn't add any parameter-specific information beyond what's in the schema. With moderate schema coverage, the baseline score of 3 is appropriate since the schema does most of the work, but the description doesn't compensate for the undocumented 'sessionId' parameter.

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 d20 death saving throw'), target ('for a character at 0 HP'), and outcome rules ('10+ success, nat 20 regains 1 HP, nat 1 counts as 2 failures'). It distinguishes itself from sibling tools like 'roll_saving_throw' by specifying the death save context.

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 explicitly states when to use this tool ('for a character at 0 HP'), providing clear context. However, it doesn't mention when not to use it or name specific alternatives among the many sibling tools, though 'roll_saving_throw' is a logical alternative for non-death saves.

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