compare_search_periods

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

With no annotations, the description carries the full burden of behavioral disclosure. It does convey the key non-obvious behavior of comparing against the preceding equal-length period, and 'compare' implies a non-mutating read operation. However, it does not explicitly state that the tool is read-only, nor mention any rate limits, required permissions, or other side effects.

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?

A single, front-loaded sentence with no filler. Every word contributes to understanding the tool's core behavior and output. Length is appropriate for the tool's complexity.

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?

Description is adequate given that an output schema exists and all parameters are documented. However, it does not clarify how gainers/losers are computed or what metric drives the comparison, and it relies on the user to infer the default 28-day window behavior from the schema. Sufficient for invocation, but not rich.

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 100%, so the baseline is 3. The description adds no parameter-specific meaning beyond what the schema already documents; it only frames the overall use case (comparing windows to find gainers/losers), which is already implied by the parameter descriptions.

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 uses a specific verb ('Compare') with a clear resource ('an analysis window with the preceding equal period') and states the intended output ('identify search gainers and losers'). This distinguishes it from raw analytics tools like search_analytics, though it does not explicitly name any sibling or contrast itself with them.

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 when the tool is useful (when you need period-over-period gainers/losers) but provides no explicit guidance on when to use it over alternatives such as search_analytics, ctr_gaps, or compare_snapshots. No exclusions, prerequisites, or routing cues are given.

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