Mixpanel 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. It states the tool queries and returns data, implying a read-only operation, but doesn't address permissions, rate limits, error handling, or data freshness. For a query tool with zero annotation coverage, 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 extremely concise and front-loaded: two sentences that directly state the action and output with zero waste. Every word earns its place, making it easy for an agent to parse quickly.

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 (7 parameters, no output schema, no annotations), the description is minimally adequate. It covers the basic purpose and output but lacks behavioral context, usage guidelines, and details on return format. With no output schema, the agent must infer the structure from 'conversion rates and drop-off at each step', which is somewhat vague.

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 already documents all 7 parameters thoroughly. The description adds no parameter-specific information beyond what's in the schema (e.g., it doesn't explain how 'where' filters interact with funnel steps). With high schema coverage, the baseline is 3 even without param details in the description.

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's purpose: 'Query a saved funnel by ID' specifies the verb (query) and resource (saved funnel), and 'Returns conversion rates and drop-off at each step' explains the output. However, it doesn't explicitly differentiate from sibling tools like 'list_funnels' or 'query_insights', which would require a 5.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools like 'list_funnels' (for listing funnels) or 'query_insights' (for other analytics), nor does it specify prerequisites or exclusions. This leaves the agent without contextual usage information.

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