Habitica MCP Server

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. 'Buy reward' implies a transactional mutation (likely spending resources), but the description does not specify costs, side effects (e.g., inventory changes), permissions required, or response format. This leaves critical behavioral traits undisclosed.

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 overly concise to the point of under-specification. 'Buy reward' is a two-word phrase that fails to convey necessary details, making it inefficient rather than succinct. It lacks structure and does not front-load critical information, requiring the agent to infer too much.

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 the complexity of a transactional tool with no annotations and no output schema, the description is severely incomplete. It does not explain what 'buying' involves (e.g., currency, success conditions), what happens post-purchase, or return values. This inadequacy hinders effective tool use by an agent.

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 100%, with the single parameter 'key' documented as 'Reward key or ID'. The description adds no additional meaning beyond this, such as examples of valid keys or where to find them. With high schema coverage, the baseline is 3, as the schema handles parameter documentation adequately.

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 'Buy reward' is a tautology that restates the tool name without adding meaningful context. It specifies a verb ('Buy') and resource ('reward'), but lacks any elaboration on what 'buying' entails or what a 'reward' is in this system. Compared to siblings like 'buy_item' or 'get_shop', it fails to distinguish itself clearly, leaving the purpose vague.

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?

No guidance is provided on when to use this tool versus alternatives. The description does not mention prerequisites (e.g., needing currency or specific conditions), exclusions, or related tools like 'buy_item' or 'get_shop'. Without any context, an agent cannot determine appropriate usage scenarios.

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