ga4_key_events

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

Because no annotations are supplied, the description carries the full burden. It does disclose useful behavior: the required Admin API enablement, the Viewer role requirement, and that errors are self-explanatory. It does not state the read-only nature, the return shape or ordering, or pagination, and the mid-sentence Spanish phrase ('Lector (Viewer) en la propiedad de GA4') reduces clarity.

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?

It is three compact sentences with no filler, and the subject is front-loaded. The only flaw is the inconsistent language mixing, which slightly weakens readability but costs no real length.

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 single-parameter read tool with no output schema, the description covers authorization and error guidance well. It omits what the response contains (fields per key event) and whether results are paginated or limited, which the agent would otherwise need to know.

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?

There is a single optional parameter, and schema description coverage is 100%; the schema already explains that property is a saved property name defaulting to the default property. The description adds nothing about the parameter, so baseline 3 applies.

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 identifies the resource precisely: events marked as key events (formerly conversions) in the property, and it clarifies the legacy terminology, which helps recognition. It lacks an explicit verb such as 'list' or 'retrieve', so a reader has to infer that this is a read operation. It also does not distinguish this tool from its close sibling ga4_top_events.

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 gives prerequisites to run it and points to ga4_check_access as a one-shot diagnostic when access fails, which is genuine troubleshooting guidance. However, it does not say when to use this tool instead of ga4_top_events or ga4_event_counts, so routing between the event-related siblings is left to inference.

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