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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), and the description adds real value beyond them: bots are excluded from counts, and an empty result may signal a late realtime feed rather than zero traffic. That empty-result caveat is exactly the kind of non-obvious behavior an agent needs.

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?

Three tight sentences: scope first, then the enumerated dimensions and metrics, then the bots and late-feed caveats. No filler and nothing buried.

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 an output schema present, return values need no explanation, and the description covers the enumerated vocabulary the schema delegates to it plus the empty-result semantics. Minor gap: nothing about multi-server usage or the minuteRanges default beyond what the schema states.

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 coverage is 100%, but the metrics and dimensions schemas explicitly defer to the description for valid names, and the description supplies them. It says nothing about limit, orderBys, minuteRanges, or server_name beyond what the schema already states, so it adds meaning where it matters most and stays silent elsewhere.

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 and resource (runs a report) plus a precise scope: hits from the last 30 minutes. The 30-minute window implicitly separates it from the sibling run_report, though it never names that sibling 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?

The realtime window implies when to reach for this tool over run_report, but the description never states the alternative or an exclusion. An agent must infer the routing decision from the 'last 30 minutes' phrasing alone.

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