ga4_tech_breakdown

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

With no annotations, the description carries the full burden and does useful work: it states the two prerequisites (Data API enabled on the quota project, Viewer role on the GA4 property) and that access errors are self-explanatory. It never says this is a read-only operation, what the result rows contain, or how limit truncation behaves, which are the gaps an agent would still have to guess at.

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 breakdown purpose is front-loaded in the first clause, which is good. The final sentence mixes languages ("Lector (Viewer) en la propiedad de GA4") and packs prerequisites, error behavior, and a sibling pointer into one run-on, which hurts readability.

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 six-parameter analytics query with no output schema, the description covers purpose and prerequisites but omits what a result row looks like (dimension value plus user/event counts) and how `limit` affects the breakdown. Adequate to attempt a call, not complete enough to predict the response shape.

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 prose restates the breakdown choices already enumerated in the schema's `by` enum and explains the `events` filter ("optionally only for some events"), adding slight meaning. It says nothing about `limit`, `property`, or date-range interplay, so at 67% schema coverage the description does not compensate for the undocumented remainder.

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 opening clause names the metrics (users and events) and enumerates the breakdown dimensions (platform, app version, OS version, device model), which is a specific verb+resource statement. It is distinguishable from ga4_top_events and ga4_event_counts by focusing on dimensional breakdown rather than top-N or totals, though it never names those siblings explicitly.

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?

It gives a concrete use case ("spot a version or device where a step fails") and routes the agent to ga4_check_access when the failure is access-related. There is no explicit statement of when NOT to use it (e.g., when a full report or funnel is needed), which keeps it below a 5.

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