retell_create_agent

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the action 'Create' and parameter requirements but does not mention permissions, side effects, idempotency, return value, or error behavior. For a mutation tool without annotations, this is a significant transparency gap.

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 two sentences and front-loads the core purpose. Every clause adds meaningful information: the action, the resource, and the critical prerequisites. 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?

The schema is rich and covers all 11 parameters, and the description adds the essential requirement of choosing one response engine. However, the description does not mention what happens after creation (e.g., return object, how to verify via list/get) or any prerequisites like listing voices, though the schema fills some gaps. Given the good schema coverage, the description is adequate but not fully complete on behavioral outcomes.

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?

With 100% schema description coverage, the schema already documents each parameter. The description adds value by clarifying the mutual exclusivity of the three response engine parameters, stating that exactly one is required. This semantic constraint is not fully apparent from the schema alone.

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 uses the specific verb 'Create' and names the resource 'Retell AI voice agent', clearly distinguishing it from sibling tools that list, get, update, or delete agents as well as create other resource types. It also highlights essential requirements, leaving no ambiguity about the tool's primary function.

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 provides clear usage context by stating that creating an agent requires a voice_id and exactly one response engine among llm_id, llm_websocket_url, or conversation_flow_id. However, it does not explicitly compare against alternatives like retell_create_chat_agent or when not to use this tool, leaving some room for interpretation.

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