umami-compass

Analyze portfolio performance

analyze_performance_portfolio

Read-onlyIdempotent

Compare Core Web Vitals across a bounded set of websites, with confidence, event/pageview ratios, and metric-specific drill-downs to identify underperforming sites.

Instructions

Compare Core Web Vitals across a bounded website portfolio with compact-by-default output, metric-specific drill-down selection, confidence, event/pageview ratios, and precise section truncation metadata.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "start": "<start>",
      "end": "<end>"
    },
    "name": "analyze_performance_portfolio"
  }
}

Input Schema

Name	Required	Description	Default
`end`	Yes	Unix milliseconds, ISO 8601 with timezone, or YYYY-MM-DD (UTC)
`start`	Yes	Unix milliseconds, ISO 8601 with timezone, or YYYY-MM-DD (UTC)
`filters`	No
`metrics`	No
`timezone`	No		UTC
`verbosity`	No	compact returns concise per-site rows and leaders; standard adds richer per-site rows and drill-downs; full returns complete normalized per-site evidence	compact
`detailMetric`	No		lcp
`websiteLimit`	No
`comparisonMode`	No		previous
`detailRowLimit`	No
`excludeDomains`	No
`detailSiteLimit`	No
`excludeWebsiteIds`	No
`minimumEventCount`	No
`includeInsufficient`	No	Include undersized aligned drill-down rows after comparable rows
`minimumBreakdownCount`	No

Output Schema

Name	Required	Description	Default
`data`	Yes	JSON analytics data returned by Umami Compass
`meta`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Addedv0.5.2Nov 13, 2026

TDQS

B3.1/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare this as a safe, idempotent, read-only, open-world operation, so the bar is lower. The description adds useful behavioral context—"compact-by-default output" and "precise section truncation metadata"—but much of the remainder (confidence, ratios) overlaps what the output schema should convey.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

It is a single front-loaded sentence that opens with the core action, which is good. However, the trailing clause becomes a dense feature dump ("confidence, event/pageview ratios, and precise section truncation metadata") that is harder to parse than the leading action.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given 16 parameters with nested filter objects and only 25% schema coverage, the description is only moderately complete—it frames the operation and output default but leaves most parameters and their interactions unexplained. The presence of an output schema and safety annotations offsets some of the gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 25% across 16 parameters, so the description carries a real burden. It gestures at key concepts (bounded portfolio, metric-specific drill-down selection, compact default) that map to websiteLimit/excludeDomains, detailMetric/detailRowLimit, and verbosity, but it does not explain these parameters by name or supply format/behavior details, leaving much undocumented.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description gives a specific verb plus resource: "Compare Core Web Vitals across a bounded website portfolio" and enumerates output facets (drill-downs, confidence, ratios, truncation metadata). It is clearly about CWV benchmarking rather than general traffic metrics, but it never names or distinguishes itself from siblings like analyze_release_impact or get_portfolio_overview.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no explicit when-to-use/when-not guidance and no reference to an alternative tool. The only steer comes from the implied scope phrase "bounded website portfolio." An agent must infer that this is the CWV-comparison choice over sibling analytics tools.

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

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