surendranbsurendranb/google-analytics-mcp/skills/custom-dimensions/SKILL.md

custom-dimensions

Skill244 starsChanged 43 days agoMITView on GitHub

How to find and query property-specific custom dimensions in GA4.

We split this skill into the rules it gives an agent

6 rules. About 0 are common, 3 are distinctive, and 3 are very specific to this project.

≈0
Common · estimate
Many files like this have a rule of this kind.
≈3
Distinctive · estimate
This author's own choices. Worth a look.
3
Very specific
Tied to their project's names, files or tools. Probably skip.

Common
Distinctive
Very specific

Very specific:
Always call search_schema("custom") first — it will show every registered custom dimension for this exact property.
line 12
Distinctive:
If the property has not collected this parameter, the API returns an error.
line 27
Very specific:
Call search_schema("custom") — lists all registered custom dimensions.
line 38
Distinctive:
If the one you need appears, use its exact API name.
line 39
Very specific:
If it does not appear, ask the user what event parameter name their tracking code uses, then query with customEvent:that_name.
line 40
Distinctive:
If the query still fails, the parameter is not collected by this property.
line 42

≈ “Common” is an estimate: at least 1 in 5 of the 308,232 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.

Files

SKILL.md

Custom Dimensions and Event Parameters

How to find and query property-specific custom dimensions in GA4.

The core rule

Custom dimensions are property-specific. Never guess their names. Always call search_schema("custom") first — it will show every registered custom dimension for this exact property.

Two valid syntaxes

GA4 supports two ways to access custom data:

Registered custom dimensions — appear in the schema by their registered name. Find them with search_schema. Use the name exactly as returned.

Unregistered event parameters — accessed inline with:

customEvent:parameter_name for event-scoped parameters
customUser:property_name for user-scoped properties

The parameter_name must exactly match what your tracking code sends. If the property has not collected this parameter, the API returns an error.

Why guessing fails

The model cannot know what custom parameters a GA4 property uses — they are defined by the site's own tracking code and GA4 Admin settings. customEvent:page_category works on one property and fails on another depending on whether that property's tracking sends a page_category parameter.

Workflow

Call search_schema("custom") — lists all registered custom dimensions.
If the one you need appears, use its exact API name.
If it does not appear, ask the user what event parameter name their tracking code uses, then query with customEvent:that_name.
If the query still fails, the parameter is not collected by this property.

Scope matters

Scope	Syntax	Use for
Event	`customEvent:name`	per-hit data (page category, product id, etc.)
User	`customUser:name`	user attributes (plan, cohort, customer type)
Session	registered name only	session-level custom groupings

Mixing scopes can cause incompatibility errors — see the compatible-combinations skill.

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In this repository21 other files it gives its agents.
- AGENTS.mdAGENTS.md
- docs/llms-full.txtllms.txt
- docs/llms.txtllms.txt
- llms.txtllms.txt
- ga4-analyticsSkill
- ai-referral-analysisSkill
- attribution-scopeSkill
- bot-traffic-detectionSkill
- channel-acquisitionSkill
- common-metric-namesSkill
- compatible-combinationsSkill
- content-performanceSkill
- date-rangesSkill
- ecommerce-analysisSkill
- filter-structuresSkill
- ga4-limitationsSkill
- gcp-setupSkill
- geo-device-segmentationSkill
- gcp-setupSkill
- traffic-diagnosisSkill
- ua-to-ga4Skill

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