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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the description only needs to add operational context, which it does by disclosing the entitlement gate and the shape of the returned data. What happens on a non-paid plan (error vs empty list) is 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?

Two short sentences with zero waste; the return contents come first and the access restriction is placed after as a caveat. Nothing could be removed without losing information.

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 parameters, no output schema, and a read-only annotation, the description's main burden is telling the agent what comes back, which it does by naming the catalog and ICP columns. Only the failure mode for non-paid plans and rough result size are 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?

The tool takes zero parameters, so there is no parameter semantics to explain and the baseline applies. The description correctly makes no claims about filtering or arguments, implicitly signalling it returns everything.

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?

Specific verb plus resource ('List your signal sets') and it names the payload contents (signal catalog, ICP columns usable in criteria). It is clearly distinguishable from the singular getSignalSet, though it never names the sibling explicitly.

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 'Paid plans only' line is a useful eligibility constraint that tells an agent when the call will not work. However, there is no explicit guidance on when to use this versus getSignalSet, previewSignalSet, or saveSignalSet, so routing must be inferred from the verb.

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