ga_run_realtime_report

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

The readOnlyHint annotation already establishes the read-only nature. The description adds valuable behavioral context: the time window (last 30 minutes) and the default result limit, which helps the agent anticipate response size. It does not disclose rate limits or authentication prerequisites, but the annotation covers safety and the added context is sufficient for a read-only tool.

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 description is concise and front-loaded: the first line states the purpose. The token optimization warning and common dimensions/metrics are tightly packed into a few lines, with no filler. Every sentence earns its place, and the use of a warning emoji draws attention to an important cost-saving measure.

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?

The description provides enough information for a simple report tool: purpose, time window, common parameters, and size control. However, there is no output schema, and the description does not explicitly describe the response format (e.g., rows of dimension/metric values). While an agent can infer the return structure, the lack of explicit return-type guidance leaves a gap.

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 100% schema description coverage, the baseline is 3. The description adds value by listing common dimensions (city, country, deviceCategory, unifiedScreenName) and metrics (activeUsers, screenPageViews, conversions), which are not present in the schema and greatly aid the agent in constructing valid parameter values.

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?

The description clearly states the tool's function with a specific verb ('Get') and resource ('real-time Google Analytics data'), and narrows the scope to 'last 30 minutes,' distinguishing it from historical report tools like ga_run_report.

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 description clearly implies when to use this tool (for recent real-time data) and includes a token optimization tip about using 'limit' to control result size. It doesn't explicitly name alternative tools for historical data, but the 'last 30 minutes' scoping provides contrast with ga_run_report and similar siblings.

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