Create saved segments or cohorts in Umami Analytics by defining filters, match rules, and optional date ranges to target specific website audiences.
Create a saved segment or cohort
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| type | Yes | ||
| websiteId | Yes | ||
| parameters | Yes |
Changes observed during successful MCP inspections.
v2.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the behavioral burden. It never says whether creation is idempotent, whether names must be unique, what permissions are required, or what limits apply to cohorts versus segments. It only repeats the resource being created.
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?
One short front-loaded sentence with no wasted words, but the brevity is under-specification rather than economy—it omits information the agent needs.
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 mutation tool with nested objects, 4 required params, no annotations, and no output schema, the description is far too thin. An agent cannot know the valid shape or constraints of a segment/cohort creation from this.
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% and the tool has four required parameters with nested objects. The description contributes nothing about 'parameters', 'match', 'action', 'filters', or the segment-vs-cohort constraints, leaving the undocumented schema to speak for itself.
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?
States a specific verb ('Create') and resource ('saved segment or cohort'), and the type enum in the schema matches. It is implicitly distinguishable from the list/get/update/delete_segment siblings, though the description doesn't explicitly reference them.
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 on when to choose this over alternatives, no prerequisites, no mention of how 'segment' differs from 'cohort'. The agent is left to infer usage entirely from the name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.