dnc_check

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

With no annotations provided, the description fully bears the burden of behavioral disclosure. It explains the scope of the lookup (global federal/state lists, platform-curated entries, per-org entries) and the return values (blocked status, source list, timestamps), which goes well beyond a minimal description.

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?

The description is well-organized with a clear lead sentence, followed by behavioral details, a usage warning, and a parameter section. Every sentence adds value, and there is no redundant or filler content.

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 low-complexity tool with one parameter, the description is complete: it explains the purpose, directory scope, return values, and when to use it. An output schema exists to handle the return shape, so no further detail is necessary.

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 input schema only defines 'phone' as a required string with no description schema coverage. The description compensates by specifying the E.164 format and providing a concrete example (+12125551234), giving the agent essential parameter semantics.

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 clearly states a specific action and resource: 'Check a phone number against the platform DNC directory.' It also distinguishes itself from sibling DNC management tools by focusing on single-number lookup and explicitly listing the returned information.

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 provides explicit guidance on when to use: 'Always check before placing an outbound call to a new contact' and explains the regulatory consequence. It does not name alternatives, but the intended usage context is unambiguous.

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