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

Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavioral facts beyond the annotations: the 80-store threshold, the exact response payload, the no-write guarantee, and a plan-tier restriction ('Paid plans only') that affects whether the call will succeed at all. Only error/failure behavior and rate limits are left unstated.

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?

Three short sentences, each earning its place: purpose and threshold first, return shape second, side-effect and eligibility constraints last. No filler or redundancy, though the flow would read slightly better with the paid-plan constraint grouped with the other usage conditions rather than trailing as an afterthought.

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?

This tool has a nested-object parameter and no output schema, so the description compensates by stating the return shape {"enough": true|false} explicitly along with the threshold used to compute it. Combined with the no-persistence guarantee and the paid-plan gate, an agent has everything needed to decide to call it and interpret the result.

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 100%, and the criteria schema already spells out both the recursive node form and the flat form in detail. The description adds no meaning beyond that for either criteria or setId, so the baseline of 3 is appropriate when the schema carries the full burden.

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 verb and resource ('check whether candidate signal criteria match enough stores') and pins the criterion to a concrete threshold (80 or more). It implicitly separates itself from saveSignalSet by stating 'It does not save anything,' so an agent can tell this is a dry-run evaluation rather than a persistence call.

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?

Usage context is clear: this is a pre-save validation step, reinforced by the explicit 'does not save anything' clause that points the agent at saveSignalSet for persistence. It stops short of stating explicit when-not conditions or naming the alternative tool outright, so it is strong but not fully prescriptive.

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