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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful content context ('with the prompts and sources behind it'), but says nothing about date-range scoping, engine filtering, or pagination behavior for what is clearly a filtered read.

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 short sentences, front-loaded with what is read and followed by the key dependency. No filler, no repetition 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?

For an 8-parameter tool with 0% schema coverage and no output schema, the description should explain the date range, engine/category filters, and projectId/siteId scoping. It covers only brandKey's origin, leaving most of the call contract unstated.

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, including two enums (engine/engines, category) and date-time from/to fields. The description only explains the provenance of brandKey and leaves every other parameter's meaning and format to inference, so it fails to compensate for the coverage gap.

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') and implies the single-competitor scope that separates it from the sibling list tool get_ai_visibility_competitors, which it names. The differentiation is present but relies on the word 'one' rather than an explicit contrast.

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?

The sentence 'brandKey comes from get_ai_visibility_competitors' gives a real prerequisite/chain hint, which is more than nothing. However, it never states when to drill into one competitor versus alternatives (e.g. overview or citations tools), so usage is only implied.

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