Compare Periods

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

Annotations already establish readOnlyHint=true and destructiveHint=false, so no contradiction exists. The description adds value beyond annotations by stating the return type (delta calculations) and enforcing a data-only analysis rule, which is useful for agents using the response.

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 concise and front-loaded: purpose, output, use cases, then a critical guidance note. Every sentence earns its place, and there is no redundant filler.

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 comparison tool with no output schema, the description sufficiently describes the returned metrics and sets expectations for data-driven analysis. Minor gaps remain around delta sign conventions and exact response shape, but the tool is still completely invocable from the information provided.

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 88%, so the structured schema already documents most parameters. The description mentions 'two date ranges' and the computed metrics but adds little parameter-level meaning beyond what the schema provides. 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 opens with a specific verb and resource ('Compare search performance between two date ranges') and names the exact output metrics (deltas for clicks, impressions, CTR, position). This inherently distinguishes it from single-period analytics tools like search_analytics, even though no sibling is named explicitly.

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 clear use cases: tracking SEO changes, algorithm updates, and seasonal trends. It provides good context for when to select this tool, though it does not explicitly state when not to use it or name alternatives.

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