Analytics report

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

Annotations already declare readOnlyHint and destructiveHint, so the safety profile is covered. The description adds behavioral context beyond the annotations: the property_id fallback to config, accepted date-format strings, and common dimensions/metrics. No contradiction with annotations.

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?

Four short lines, front-loaded purpose, and every sentence adds practical value. The common-values lists are compact and scannable, and no filler or restatement of the schema is present.

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?

Given the output schema exists, return-value documentation is not the description's job. It covers date syntax, common fields, and config fallback. It is slightly incomplete in not clarifying what null metrics/dimensions default to or when the realtime sibling is the right choice, but these are minor for an optional-parameter read-only report tool.

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 0% schema description coverage, the description carries the parameter-documentation burden. It compensates well by listing common dimension and metric values and specifying accepted date formats, and it explains the property_id default. The only gap is limit, whose default value is visible in the schema.

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 opens with a specific verb and resource: 'Run a custom GA4 report with specified dimensions, metrics, and date range.' This is clear and identifies the GA4 reporting domain, though it does not explicitly differentiate from the sibling run_realtime_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 gives useful context (common dimensions/metrics, date formats, property default) but never says when to prefer this tool over alternatives like run_realtime_report or run_gsc_report. Usage is implied by 'custom GA4 report' rather than stated with exclusions.

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