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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds the analytical threshold concept ('meaningful share of impressions'), which hints at the min_share/min_impressions cutoffs, but says nothing about data source, latency, or result size beyond the schema's defaults.

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 compact clause with no filler, and the defining condition (2+ pages, meaningful impression share) is front-loaded. It is slightly under-specified rather than padded, but nothing is wasted.

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 read-only report with 7 parameters and no output schema, the description omits what a caller gets back (query, competing URLs, impression split) and whether a Search Console connection is required. The threshold logic is covered, so the remaining gaps are moderate rather than severe.

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 71% and the schema already documents site, range, dates, and min_share explicitly. The description only reinforces the min_share/min_impressions concept via 'meaningful share of impressions'; it adds nothing about limit, pagination, or how 'share' is computed per page.

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 names a specific analytical output — queries where two or more of the user's pages take a meaningful share of impressions — which is concrete enough to separate it from siblings like report_brand_split or report_content_decay. It is phrased as a noun clause rather than a verb+resource statement, so the action (run a cannibalization report for a site) is implied rather than stated.

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?

There is no when-to-use guidance, no prerequisites (e.g. requires a connected Search Console property), and no mention of alternatives. The agent must infer from the phrase 'splitting ranking signals' that this is a diagnostic for SEO overlap issues.

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