Schedule Email

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

Adds retry behavior (3 attempts) beyond annotations. Annotations already indicate non-destructive write operation; description clarifies reliability mechanism.

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?

Three concise sentences with critical constraints (time range, retry, sibling tools) front-loaded. No wasted words.

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?

Covers core behavior, time bounds, retry, and related tools. Output schema exists, so return format is covered. Could mention attachment format but sufficient for agent decision.

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 coverage is 82%, so baseline is 3. Description adds time constraints for send_at and hints at ISO 8601 format, but other parameters (cc, attachments, etc.) are left to 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?

Description clearly states the tool schedules email for future delivery with specific time constraints (60 sec to 30 days). It distinguishes itself from siblings like list_scheduled_emails and cancel_scheduled_email.

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 recommends list_scheduled_emails and cancel_scheduled_email for related actions. Does not explicitly contrast with send_email for immediate delivery, but context implies use for future scheduling.

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