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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, and the description adds real context on top: the fixed 30-day window, the account-connection prerequisite, and the important caveat that counts are a floor because some assistants send no referrer. That data-quality warning is information an agent cannot get from the annotations or schema.

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?

Four short sentences, each doing distinct work: prerequisite, use case, return contents, and the accuracy caveat. The use-case trigger and the returned dimensions are front-loaded with no filler.

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?

An output schema exists, so return values need not be spelled out, yet the description still tells the agent the shape (by assistant, by landing page, plus install snippet). With one parameter, no nesting, and annotated safety, nothing an agent needs to invoke this correctly is missing.

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?

There is a single required parameter with 100% schema description coverage, and the schema already explains that businessId comes from list_monitored_businesses. The description only restates "Needs businessId" without adding format, scoping, or error semantics, so baseline 3 applies.

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: returns the last 30 days of website visits that came from AI assistants, broken down by assistant and landing page. Nothing in the sibling list (share of voice, visibility report, website fixes) returns referral traffic, so an agent can route to this tool 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 an explicit natural-language trigger ("are people arriving from ChatGPT?") plus two prerequisites: a connected MentionedOn account and a businessId. It stops short of naming when NOT to use it or pointing to an alternative for non-AI traffic, so it is clear context rather than full routing guidance.

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