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

No annotations are provided, so the description carries full responsibility for behavioral disclosure. It only says it's a 'query', which implies read-only, but doesn't explicitly state side effects, permissions, or response behavior. The schema does mention has_more/next_start_row, but the description itself doesn't add that.

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?

Two sentences, purpose front-loaded, no filler. Each sentence carries distinct information: the tool's role and the parameter compatibility.

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 an 8-parameter tool with no output schema and no annotations, the description is too thin. It doesn't describe the response shape, pagination, error behavior, authentication, or any prerequisites. Its only guidance is the 'other tools' scope, which is usage guidance, not completeness.

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 baseline is 3. The description adds meaningful context that parameters are exactly the ones the Google API accepts (same dates, dimensions, filters), which helps an agent with API knowledge. It also reinforces that the tool exposes the raw API surface.

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 states a specific operation ('Direct Search Analytics query') and explicitly scopes it as the catch-all for questions the other tools do not shape, which differentiates it from siblings. However, it could be clearer about what 'Direct' means and what the resource is.

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 a clear usage condition: use when other tools do not shape the question. It doesn't name alternatives or list when-not-to-use cases, but the implied rule is strong enough for an agent to decide.

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