Fabits MCP Server

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

No annotations are provided, so the description carries full burden. It mentions 'Invest' implying a financial transaction, but lacks details on permissions, authentication needs, rate limits, or potential side effects (e.g., payment processing, confirmation). This is inadequate for a tool that likely involves sensitive operations.

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, efficient sentence that gets straight to the point without unnecessary words. It's appropriately sized for the tool's complexity, though it could be more informative.

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 insufficient for a tool with 5 required parameters and likely financial implications. It lacks details on behavior, return values, error handling, and how it integrates with sibling tools, leaving significant gaps for an AI 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%, so the schema fully documents all 5 parameters. The description adds no additional meaning about parameters beyond implying 'action plan' relates to 'plan_id'. Baseline 3 is appropriate as the schema handles parameter documentation.

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 states the action ('Invest in action plan') and method ('via one-time lumpsum'), which is clear but somewhat vague. It doesn't specify what 'action plan' means in this context or how it differs from similar tools like 'fabits_invest_basket' or 'fabits_invest_lumpsum', missing sibling differentiation.

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. With multiple investment-related tools in the sibling list (e.g., 'fabits_invest_basket_sip', 'fabits_invest_lumpsum'), the description fails to indicate specific contexts, prerequisites, or exclusions for this one-time lumpsum method.

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