Compare two periods in Search Console

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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive behavior. The description adds output behavior ('returns rows with deltas, sorted by biggest click change'), providing transparency without contradicting 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 a single, tightly worded sentence with no redundancy. It efficiently conveys the core function and output, making it easy for an agent to parse and act on.

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 tool with 10 parameters, the description plus parameter-specific notes (e.g., date formats, data lag) provide sufficient context. The lack of an output schema is acceptable, but the dimension mismatch between the description and schema slightly reduces 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 descriptions cover 70% of parameters with helpful notes like data lag and example values for siteUrl and expression. However, the description misleadingly limits dimension to 'query or page' while the schema permits country/device, and dimension/searchType lack descriptive text, reducing semantic clarity.

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 'Compare search performance between a current and a previous period' with a specific action and resource. It distinguishes from sibling tools by focusing on period-over-period deltas for a single dimension, making it uniquely identifiable among similar GSC 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 description implies usage when comparing two date ranges but does not explicitly mention alternatives or conditions. It lacks guidance on when to use this tool versus other GSC tools like gsc_search_analytics or gsc_opportunities, leaving the choice to the agent.

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