Fabits MCP Server

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

With no annotations, the description carries full burden but only states 'Initiate', implying a write operation without details on permissions, side effects (e.g., payment initiation, confirmation steps), or error handling. It misses critical behavioral traits like whether it triggers immediate payment or requires follow-up actions.

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 core action without unnecessary words. It earns its place by succinctly conveying the tool's purpose.

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 financial transaction tool with 6 required parameters and no annotations or output schema, the description is inadequate. It lacks details on behavioral outcomes (e.g., what happens after initiation), error cases, or integration with sibling tools like 'fabits_complete_lumpsum_upi', leaving gaps in understanding.

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 parameters are well-documented in the schema. The description adds no extra meaning beyond implying UPI usage, which is already clear from the tool name and parameter 'upi_id'. Baseline 3 is appropriate as the schema handles most semantics.

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 action ('Initiate') and resource ('UPI lumpsum investment'), making the purpose evident. It distinguishes from siblings like 'fabits_invest_lumpsum' by specifying the UPI method, though it doesn't explicitly contrast with all investment tools (e.g., 'fabits_invest_basket').

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 like 'fabits_invest_lumpsum' (non-UPI) or other investment methods. The description lacks context about prerequisites, timing, or exclusions, leaving usage unclear.

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