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 'shows how often users perform an event' but doesn't describe output format, pagination, rate limits, authentication needs, or whether it's read-only or destructive. For a tool with 7 parameters and no annotations, this leaves critical behavioral traits undocumented.

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 appropriately concise with two sentences that efficiently convey the core purpose. It's front-loaded with the main action ('Get a frequency report') and avoids unnecessary details. However, the parenthetical '(addiction report)' adds minor ambiguity without clear explanation.

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 tool's complexity (7 parameters, no output schema, no annotations), the description is incomplete. It doesn't address output format, error conditions, or behavioral constraints. While the schema covers parameters well, the description fails to provide sufficient context for safe and effective use, especially compared to sibling tools.

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 parameters thoroughly. The description adds minimal value beyond the schema by implying the report analyzes 'users' and 'events', but it doesn't explain parameter interactions or provide additional context. The baseline score of 3 is appropriate when the schema does the heavy lifting.

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: 'Get a frequency report (addiction report). Shows how often users perform an event within a time window.' It specifies the verb ('Get'), resource ('frequency report'), and scope ('users perform an event within a time window'). However, it doesn't explicitly differentiate from sibling tools like 'query_events' or 'top_events' that might also involve event analysis.

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 mentions the general context ('frequency report') but doesn't specify use cases, prerequisites, or exclusions. With many sibling tools available for event analysis (e.g., 'query_events', 'top_events'), the lack of comparative guidance is a significant gap.

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