ChartMogul 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 and does well by disclosing critical behavioral traits: ARR values are in integer cents (requiring division by 100), the return format includes an entries array and summary object, and it provides a concrete example. However, it lacks details on rate limits, authentication needs, or error handling.

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 front-loaded with key information (purpose and critical note about cents), followed by details on returns, parameters, and an example. It is appropriately sized with no wasted sentences, though the formatting could be slightly more structured for readability.

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 (6 parameters, no annotations, no output schema), the description is largely complete: it covers purpose, critical data format, return structure, all parameters with semantics, and an example. It lacks only minor details like pagination or error scenarios, but is sufficient for effective use.

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 0%, so the description must compensate, which it does excellently. It explains all parameters: required ones (start_date, end_date, interval with allowed values), optional ones (geo, plans, filters with syntax guidance and reference to another tool), and provides an example for clarity.

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 retrieves Annual Recurring Revenue metrics from the ChartMogul API, specifying the exact calculation (ARR = MRR × 12) and distinguishing it from sibling tools like 'mrr_metrics' and 'all_metrics' by focusing specifically on ARR.

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 implies usage by specifying required parameters and mentioning an optional 'filters' parameter that references 'get_cfl_fields' for field lists, but it does not explicitly state when to use this tool versus alternatives like 'mrr_metrics' or 'all_metrics'.

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