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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral detail beyond annotations: top-N truncation by the first metric, row_limit max 100, column_limit max 25, total-count reporting, and totals inclusion.

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 front-loaded and efficient, covering purpose, layout, limits, and totals in one main sentence. The trailing revision string is not useful for invocation and is the only notable waste.

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 9-parameter read-only report tool with a low schema-description coverage but an output schema, the description provides enough behavioral context to call it correctly. Minor gaps remain around date format and dimension/metric naming, but the core invocation semantics are present.

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 only 22%, so the description must compensate. It explains rows, columns, metrics, property format, row_limit/column_limit semantics, truncation by first metric, and totals behavior, though it does not specify date formats or accepted dimension/metric naming conventions.

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?

Clearly identifies a GA4 cross-tab/pivot report and explains its layout: rows dimensions down the side, columns across, metrics in cells. It distinguishes itself from a standard report by explicitly describing cross-tab structure, though it does not name sibling tools.

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 cross-tab description implies when the tool is appropriate, but there is no explicit guidance on when to prefer it over ga4_run_report, ga4_run_cohort_report, ga4_run_funnel_report, or ga4_run_realtime_report. Usage is inferable but not stated.

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