Fabits MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions the return format ('top matching funds with key metrics') but lacks details on authentication needs, rate limits, error handling, or session state implications. For a search tool with user_id as required, this is a significant gap in transparency.

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 front-loads the purpose and outcome without unnecessary details. Every word contributes to understanding the tool's function, making it appropriately sized and well-structured.

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 search tool with 3 parameters, no annotations, and no output schema, the description is adequate but incomplete. It covers the basic purpose and return format but lacks details on behavioral aspects like authentication or error handling, which are crucial for a tool with a required user_id parameter.

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%, providing clear documentation for all parameters. The description adds minimal value beyond the schema, as it doesn't elaborate on parameter interactions or search behavior. Baseline 3 is appropriate since the schema does the heavy lifting, though no extra context is provided.

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 verb ('search') and resource ('mutual funds') with specific search criteria ('by name, category, or keywords') and outcome ('returns top matching funds with key metrics'). It distinguishes from siblings like 'fabits_get_fund_details' by focusing on search rather than retrieval of specific fund details, though it doesn't explicitly name alternatives.

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 explicit guidance on when to use this tool versus alternatives like 'fabits_get_star_funds' or 'fabits_get_fund_details'. The description implies usage for searching funds but lacks context about prerequisites, timing, or exclusions, such as whether it's for initial discovery or ongoing research.

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