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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered structurally. The description adds the useful disclosure that the result set is unbounded-in-principle ('every event this app has ever sent') and flags the capture-switched-off field, but says nothing about pagination, truncation, or result size for what could be a very large catalog.

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?

Two sentences, no filler. The return contents come first, the usage guidance and its rationale second, which is the right ordering for an agent deciding whether to call it.

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?

With no output schema, the description correctly spends its words describing what comes back and why it matters. The only shortfall is the absence of any note on volume, pagination, or whether capture-disabled events are included by default versus filterable.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; the schema is empty and coverage is 100%. Baseline 4 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 precisely what the resource is (every event the app has sent) and what each row carries: volume, last-seen, and capture-disabled status. No sibling tool covers event instrumentation, and an agent can immediately tell this is the event catalog read rather than an analytics or experiment query.

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 trigger — call this before adding instrumentation — plus the reason (avoid near-duplicate event names) and a downstream consequence (the name mirrors the experiment's primary metric string). That is a genuine when-to-use, and no alternative tool exists to route away from.

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