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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds real value by hinting at return content (prompts and sources behind the score), which matters because there is no output schema, but says nothing about default date range, result volume, or pagination.

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 tight sentences with the core purpose front-loaded; the brandKey prerequisite follows as a constraint. No filler or restatement of the title.

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 8 undocumented parameters, no output schema, and date filters and engine selection being central to an analytics query, a two-sentence description is thin. The agent cannot know whether omitting from/to yields a default window or how engine and engines interact.

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 0% across 8 parameters, so the description carries the full burden — yet it only explains brandKey. The from/to window, the single engine vs. engines array distinction, category, and the required siteId/projectId pairing are all left for the agent to guess.

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 and resource ("Read one brand's visibility against the user's") plus the payload shape ("with the prompts and sources behind it"). Naming the source of brandKey as "the AI visibility competitors list" implicitly separates it from the sibling list tool get_ai_visibility_competitors.

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 clear context: this is a per-competitor drill-down and brandKey must come from the competitors list, which tells the agent the correct call order. It stops short of stating when not to use it, i.e. no pointer to get_ai_visibility_overview, get_ai_visibility_citations, or get_ai_visibility_competitors as alternatives.

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