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

Annotations already establish read-only, idempotent, non-destructive behavior, so the bar is lower. The description still adds meaningful context the annotations don't carry: the required Bearer dashboard token, the Pro subscription gate, snapshot freshness ('latest Pro report'), and the data scope ('the domain on your subscription').

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 sentence that front-loads the payload (what the tool returns) before trailing the operational caveats about Pro and tokens. Efficient and waste-free, though the trailing clauses make it dense and slightly run-on.

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 no output schema, the description does the right thing by describing the returned content (products, cited sites, appearance counts). Auth and plan gating are covered, so an agent has enough to attempt the call; only the distinction from cited_sites is left implicit.

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 are zero parameters, so per the rubric the baseline is 4. Nothing in the schema needs compensating for, and the description correctly indicates the tool is implicitly scoped to the subscription's domain rather than requiring an argument.

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 the specific resource it returns: the products AI assistants cite instead of yours, plus the sites they cite, each with an appearance count. This is clearer than a vague 'get competitors' label and partially differentiates it from siblings, though it never explicitly contrasts itself with cited_sites, which overlaps on the 'cited sites' half.

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?

It gives a real precondition ('Needs FrontStat Pro', 'from your latest Pro report', Bearer token) but never says when to choose this over get_visibility or cited_sites, nor when it is not applicable. Usage is implied by the prerequisites rather than stated as a routing rule.

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