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

Annotations include destructiveHint: true, but description does not address destructive behavior. Description adds positive details about dialing, reminders, retries, which is useful but doesn't fully explain side effects. No annotation contradiction.

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 sentences, front-loaded with purpose, no unnecessary words. Every sentence adds value.

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?

Missing explanation of return value (e.g., whether it returns a call ID). No output schema provided. Also lacks error cases or prerequisites. Acceptable for a simple tool but incomplete.

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 covers all 8 parameters with descriptions. Description adds valuable context: E.164 format for phone_number, timezone-dependent string format for scheduled_at, and example values. Greatly aids correct parameter entry.

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?

Clearly states the tool schedules a callback instead of immediate calling, with specific verb 'schedule'. Distinguishes from sibling tools like schedule_sms and make_ai_call by focusing on callbacks.

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?

Explicitly says 'Use this to book a callback for later', providing clear usage context. Does not explicitly list alternatives or when not to use, but implies contrast with immediate calling.

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