gsc_compare_periods

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the bar is lower. The description adds a useful behavioral detail: it can use an explicit previous range or fall back to the immediately preceding equal-length period. This adds some context beyond 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, concise sentence with no filler. Every word contributes to understanding the tool's purpose, and the key distinction (explicit vs. preceding equal-length) is front-loaded.

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?

The tool has 11 parameters and no output schema, yet the description doesn't mention what the output looks like, how the comparison results are structured, or what dimensions/aggregations are applicable. It is too sparse for a tool of this complexity.

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 description clarifies the core date parameters: 'current' and 'previous' ranges, specifying that if no previous range is given, it defaults to the equal-length preceding period. However, with schema description coverage at only 9%, the description should explain more of the 11 parameters, such as dimensions, filters, or type, but does not.

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's function: comparing a date range with either an explicit previous range or the preceding equal-length period. It uses a specific verb ('compare') and a resource ('date range'), and distinguishes itself from sibling query tools that focus on single-period data.

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?

No explicit guidance is provided on when to use this tool versus alternatives like gsc_diagnose_traffic_drop or gsc_detect_content_decay. The description states what it does but gives no context for selecting it over other tools.

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