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

Annotations already establish the safety profile (readOnly, idempotent, non-destructive), so the bar is lower, and the description still adds real context: the $0.001/call price, the hourly cadence, and the exact shape of what comes back. It stops short of latency or sourcing/refresh details, which is the only remaining gap.

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 cost/positioning hook is front-loaded and the routing sentence is tight, but "health/probe call" and "cheap heartbeat" restate the same idea, and the parenthetical class list is long for the value it adds.

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?

There is no output schema, so the description must carry the return contract — and it does, naming the by-class counts, the top-three severe events with impacts, and open venues. Combined with usage and cost, an agent has everything needed to call it correctly.

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?

With zero parameters and 100% schema coverage, there is nothing to disambiguate; baseline 4 applies. The description correctly does not invent parameter guidance.

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?

It states a specific verb and resource — counts of events in the feed over the last hour, broken out by class — and enumerates the other payloads (top 3 severe with impacts, venues open). It also names the exact siblings it is not (events_since, brief), so an agent can route correctly without opening either schema.

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?

"Use it every hour to decide whether anything needs a deeper look, or as a health/probe call" gives an explicit cadence and trigger, and the closing clause names the alternatives and the condition that selects them (events_since for the events themselves, brief for one asset). Nothing 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.