ga4_run_realtime_report

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds the meaningful 30-minute live window constraint and an error-recovery path via ga4_get_metadata, but says nothing about quotas, sampling, or how results are shaped.

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 compact sentences with zero filler: what it does, when to use it, and where to go instead. The purpose and the live-window scope are front-loaded before the routing advice.

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 three-parameter read-only report tool with full schema coverage and no output schema, the description covers scope, trigger, and fallbacks adequately. Return shape and pagination are not addressed, though the caller has no output schema to rely on.

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% with examples for metrics, dimensions, and property_id, so the schema carries parameter meaning. The description adds no syntax or constraint detail beyond what the schema already documents, making the baseline 3 correct.

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 (Run), resource (GA4 realtime report), and scope (active users and on-site activity from the last thirty minutes). It is clearly distinguishable from the sibling ga4_run_report, which it names 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?

Gives an explicit trigger condition ("Use when the user asks who is on the site right now") plus two routing rules: ga4_run_report for older date ranges and ga4_get_metadata for rejected realtime metric names. When-to-use, when-not, and alternatives are all covered.

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