place_call

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behaviors: it's a paid service requiring payment ID, has a phone number matching requirement, and supports TTS or audio files. However, it lacks details on error conditions, rate limits, pricing beyond durationMinutes, or what happens if the call fails.

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 appropriately sized and front-loaded, with the core functionality stated first ('Place an automated phone call...'), followed by key features and requirements. Every sentence earns its place by adding distinct value: purpose, capabilities, use cases, prerequisites, and constraints.

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 complexity of a paid phone call service with 5 parameters and no output schema, the description is moderately complete. It covers the tool's purpose, main behaviors, and prerequisites well, but lacks details on return values, error handling, or advanced usage scenarios that would be helpful for an AI agent invoking this tool.

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 100%, so the schema already documents all parameters thoroughly. The description adds minimal value beyond the schema, mentioning only that paymentId must be 'paid' (implied in schema) and phoneNumber must match create_payment (not in schema, but useful). It doesn't explain parameter interactions beyond the message/audioUrl OR relationship already in schema.

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 tool's purpose with specific verbs ('place an automated phone call', 'delivers a spoken message', 'plays an audio file') and identifies the resource ('any number worldwide'). It distinguishes itself from sibling tools like send_sms and synthesize_speech by focusing on phone calls rather than text messages or speech synthesis alone.

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 context on when to use this tool ('great for alerts, reminders, and notifications') and mentions prerequisites ('requires a valid paid payment ID', 'phoneNumber must match the one used in create_payment'). However, it doesn't explicitly state when NOT to use it or name alternatives among siblings like send_sms for text-based notifications.

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