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

With no annotations provided, the description carries the behavioral disclosure burden. It says the operation is read-only, free, paginated, and that contact details remain masked until purchase. This meaningfully informs an agent about side effects and cost, which is strong for a simple read tool.

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 deliver the core purpose, pagination behavior, masking caveat, and read-only/free status. Every clause earns its place, and the main action is front-loaded.

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 a simple three-parameter read tool, the description covers purpose, behavior, cost, and the key masking caveat. It does not describe the returned payload shape, but given the absence of an output schema and the simplicity of the operation, the definition is still adequately complete.

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%, so the description must compensate, but it only says 'paginated,' which indirectly maps to limit and offset. It does not explain that slug identifies the marketplace set or describe parameter formats, defaults, or constraints. The tool name helps, but individual parameters are largely undocumented.

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 opens with a specific verb-resource pair: 'Paginated preview of the contacts inside a marketplace set.' This clearly distinguishes it from sibling tools like get_audience_set (set-level info) and buy_audience_set (purchasing), and the tool name reinforces the target resource.

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 description gives clear contextual guidance: this is for previewing contacts before purchase, and the masking note ('until the set is purchased') implies when it is appropriate. It does not explicitly name alternative tools or state when not to use it, but the pre-purchase preview purpose is evident.

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