Mixpanel 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 states the tool returns 'cohort IDs, names, and metadata', which adds useful context about the output format. However, it doesn't disclose important behavioral traits like whether results are paginated, sorted, or filtered, or if there are rate limits or authentication requirements for this read operation.

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 perfectly concise with two sentences that each earn their place. The first sentence states the core action and resource, while the second provides essential output details. There's zero wasted text, and information is front-loaded with the primary purpose stated immediately.

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 simple list operation with 0 parameters and no annotations, the description is adequate but has clear gaps. It explains what the tool does and what it returns, but without an output schema, it should ideally provide more detail about the return structure (e.g., format of metadata). The lack of behavioral context and usage guidelines reduces completeness for this read operation.

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?

The input schema has 0 parameters with 100% coverage, so the baseline is 4. The description appropriately doesn't discuss parameters since none exist, and it adds value by explaining what the tool returns rather than focusing on inputs. No parameter information is needed or missing given the empty schema.

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 'List' and resource 'all cohorts in the project', making the purpose unambiguous. It distinguishes from siblings like 'list_annotations' by specifying the cohort resource, though it doesn't explicitly contrast with other list operations. The description avoids tautology by providing meaningful details beyond just the tool name.

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 prerequisites, context for use, or compare it to sibling tools like 'query_events' or 'list_funnels' that might serve similar listing purposes. The agent must infer usage from the tool name and description alone without explicit direction.

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