Detect traffic drops and rises

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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds real behavioral context beyond that: it works on daily series, and it only drills into the single largest shift for page/query attribution — an important output-scope fact since no output schema exists. No auth, quota, or date-finalization caveats are mentioned.

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?

Two sentences, no filler, with the core mechanism front-loaded and the usage cue placed last where it is easy to scan. The first sentence is dense but every clause earns its place.

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 an eight-parameter, no-output-schema tool, the description conveys the mechanism and the shape of the result (largest shift plus top pages/queries). It is short of complete on parameter tuning (minChangePct, window, top) and on what happens when no shift is found, but the essentials for invoking it correctly are present.

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 50%, and the four documented params (window, startDate, endDate, siteUrl) already carry their semantics in the schema. The description hints at metric and sensitivity ("90%", "moved most") but never explains top, type, metric, or minChangePct, so it neither compensates for the gap nor adds meaning beyond structured fields.

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 concrete verb and resource: it scans the daily Search Console series for sudden level shifts and then attributes the largest one to pages and queries. The example ("impressions falling 90% from one week to the next") makes the behavior unmistakable and clearly separates it from siblings like search_analytics or compare_periods, which report data rather than detect shifts.

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?

"Use it first when traffic looks wrong, to find when it changed and what changed" is an explicit triage directive, which is genuinely helpful for tool selection. It stops short of naming alternatives (e.g. compare_periods) or stating exclusions, so it's clear context rather than full when/when-not guidance.

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