Compare Dates

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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds genuinely non-structured behavior: the sign convention for deltas, the direction of position (lower is better), and that percentages are null when the Period 2 baseline is zero. It does not mention how many rows come back, ordering, or the 'top results' limiting behavior beyond what the schema's limit field says.

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?

Front-loaded with the purpose, then a clearly separated 'Direction' block covering the interpretive rules. Every sentence carries decision-relevant information, and there is no restatement of the name or schema fields.

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?

With no output schema, the description takes on the burden of explaining return semantics, and it does so: what deltas mean, the sign convention, and the zero-baseline null case. Combined with 100% schema coverage for inputs and annotations covering safety, an agent has enough to call and interpret this correctly.

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 coverage is 100%, so the schema already documents each parameter, setting a baseline of 3. The description adds real meaning on top by defining the semantic role of each period (analyzed vs baseline) and how deltas are computed relative to them, which the schema's terse date descriptions do not convey.

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?

States a specific verb+resource: 'Compare search performance across two date ranges.' This clearly separates it from sibling reporting tools like wsp_run_report_gsc and wsp_show_traffic_gsc, though it does not name those siblings explicitly. The purpose is unambiguous without opening the schema.

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?

Gives concrete usage direction, notably 'For a current-vs-previous comparison, pass the current period as Period 1 and the previous period as Period 2,' which is exactly the kind of when/how guidance that prevents mis-ordered calls. It stops short of stating when to use this versus run_report or show_traffic, so no explicit exclusions or alternatives are offered.

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