Mark GA4 events as key events

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

Adds real behavioral context beyond the annotations: the 30 key-event quota for standard properties, the skip-if-already-marked behavior (consistent with idempotentHint=true), and the fact that the counting method is fixed at creation time. It does not describe a rollback/undo path or what the response looks like, which keeps it from a 5.

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?

Four sentences, front-loaded with the action and its payoff, then the UI-gap rationale, then quota/skip caveats, then dryRun. Every sentence carries information an agent would otherwise have to infer.

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 mutating, idempotent, quota-limited tool with no output schema, the description covers purpose, limits, skip behavior and preview mode. The one remaining gap is the shape of the result (which events were created versus skipped), which dryRun only partially implies.

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 100%, so propertyId, events, countingMethod and dryRun are already well documented with examples and an enum for countingMethod. The description only restates counting method choice and dryRun at a high level, adding marginal semantics over the schema; 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?

States a specific verb (mark) and resource (events as key events/conversions in a GA4 property) plus the downstream effect on keyEvents metrics, conversion reports and Google Ads imports. Easily distinguished from the neighboring GA tools like ga_property_config and ga_create_custom_dimension.

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?

Gives an explicit when-to-use trigger (freshly instrumented event that hasn't yet appeared in the last days of traffic) versus the UI path, and an explicit prerequisite: check ga_property_config keyEvents first against the 30-key-event limit. It also notes that already-marked events are skipped and points at dryRun for a preview.

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