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 of behavioral disclosure. It states the tool 'creates a group of NPCs,' implying a write/mutation operation, but does not address permissions, side effects (e.g., whether NPCs persist in a database), error handling, or response format. The example hints at input structure but lacks behavioral context.

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 and front-loaded: the first sentence states the purpose, followed by role flexibility, and ends with a detailed example. The example is lengthy but necessary to demonstrate usage. No extraneous information is included, making it efficient for an agent to parse.

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?

Given no annotations and no output schema, the description is moderately complete. It covers the purpose and provides an input example, but lacks details on behavioral aspects (e.g., what happens after creation, error conditions) and output format. For a mutation tool with 3 parameters, it meets minimum viability but has clear gaps in transparency.

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%, with parameters 'locationName' and 'npcs' described in the schema, but 'sessionId' undocumented. The description adds value by clarifying 'roles are flexible strings' with examples (e.g., 'blacksmith'), and provides a concrete JSON example that illustrates the structure and optional fields like 'race' and 'behavior'. This compensates well for the partial schema coverage.

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: 'Generate NPCs for a settlement or location. Creates a group of NPCs with specified roles.' It specifies the verb ('generate'/'create'), resource ('NPCs'), and context ('settlement or location'), but does not explicitly differentiate from sibling tools like 'create_character' or 'spawn_populated_location', which might have overlapping functionality.

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 usage guidance. It mentions roles are 'flexible strings' and gives an example for populating a village, but does not specify when to use this tool versus alternatives (e.g., 'create_character' for single NPCs, 'spawn_populated_location' for pre-configured locations). No explicit when-not-to-use or prerequisite information is provided.

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