make_outbound_call

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

No annotations are provided, so the description carries the full burden. It mentions that the tool 'Returns: call details,' which adds some behavioral context, but it fails to disclose critical traits like whether this is a read-only or destructive operation, authentication needs, rate limits, or error handling. For a tool that initiates calls, this is a significant 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 front-loaded and efficiently structured in two sentences: one stating the purpose and return, and another providing usage context. Every sentence adds value without redundancy, making it appropriately sized for the tool's complexity.

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?

Given the tool's complexity (initiating calls with 3 parameters), no annotations, and no output schema, the description is incomplete. It lacks details on behavioral traits, parameter meanings, and expected outputs, making it inadequate for an agent to fully understand how to use this tool correctly.

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 for undocumented parameters. It does not add any meaning beyond what the input schema provides (e.g., explaining what 'agent_id' or 'to_number' represent). The description only mentions the tool's purpose and usage, leaving all three parameters semantically unclear.

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 the action ('Initiates phone call') and the resource ('with agent'), making the purpose understandable. It distinguishes this tool from siblings by focusing on outbound calling, though it doesn't explicitly contrast with similar tools (e.g., 'play_audio' or 'text_to_speech').

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 clear context for when to use the tool ('making automated calls via Twilio integration'), which helps differentiate it from other voice-related tools. However, it lacks explicit exclusions or alternatives, such as when not to use it or what other tools might be better for different scenarios.

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