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

Beyond the readOnly/openWorld annotations, it discloses the data-source resolution logic (direct Google when a service account exists, otherwise SEObolt), that each result reports its `source`, and exactly what happens when no integration is present ('says so and returns no data'). This is substantive behavioral context that annotations alone do not convey.

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 core purpose and view breakdown are front-loaded, and each sentence carries information. It is dense and slightly run-on in the integration paragraph, but nothing is wasted.

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 no output schema, the description takes responsibility for describing return contents per view, the automatic previous-period comparison, and the `source` field. An agent has everything needed to call it and interpret the result.

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%, so the baseline is 3, but the description adds real meaning by explaining what each view enum value returns and that start/end should be paired. It leaves limit semantics to the schema, which already documents them well.

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 names the specific resource (GA4 data for one site) and enumerates the three views with the exact metrics each returns, including units for duration and bounce rate. An agent can distinguish this analytics reader from search-performance siblings without opening the schema.

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?

It gives clear context for when this applies (a GA4 property linked via SEObolt or a connected Google service account) and states the default window. It does not explicitly route the agent to an alternative sibling for search-query data, so it stops short of full when/when-not guidance.

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