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

The annotations already establish this as a safe read-only, idempotent operation. The description adds the prerequisite that Google Search Console must be connected and provides actionable setup instructions, which is useful behavioral context. It does not detail response structure or rate limits, but that's not necessary given the 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?

The description is three sentences, each serving a distinct purpose: defining the data returned, suggesting use cases, and providing a setup prerequisite with an action. No wordiness or redundancy; front-loaded with the primary function.

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 straightforward 3-parameter read tool with strong annotations, the description is quite complete. It explains what data is returned, provides use cases, and addresses setup requirements. It doesn't describe the output format, but no output schema exists and the metric list already sets expectations.

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?

The input schema already documents each parameter ('site', 'startDate', 'endDate') with clear descriptions, so the schema coverage is 100%. The description adds no additional parameter-level details beyond mentioning 'date range' and 'daily', which doesn't enhance schema semantics. Thus baseline 3 is appropriate.

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 retrieves daily search performance trends with specific metrics (clicks, impressions, CTR, position) over a date range. While it doesn't explicitly name sibling tools, the combination of metrics and daily granularity effectively distinguishes it from other GSC tools like country or device breakdowns.

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 provides clear use cases ('spotting ranking changes, traffic drops, or algorithm update impact') and prerequisite guidance (GSC must be connected, with a link to the integration page). However, it does not explicitly state when not to use it or mention alternatives, such as using a query-specific trend tool for keyword-level analysis.

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