Schedule Email

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

Annotations (readOnlyHint=false, idempotentHint=false, destructiveHint=false) indicate mutation but no idempotency or destruction. Description adds valuable retry behavior: definite failures retried up to 3 times, ambiguous deliveries never retried. This goes beyond the annotations, though it does not cover potential side effects like rate limits or credit consumption.

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 with no wasted words. The key constraints and retry policy are front-loaded, and the reference to sibling tools is efficient. 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?

With 11 parameters (4 required) and an existing output schema, the description covers scheduling constraints, retry behavior, and related tools. It does not describe the output format or errors, but that is acceptable since an output schema is present. Slight gap: missing note that the email might be sent from a specific account, but the 'account_id' parameter is documented in the schema.

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 most parameters have descriptions in the schema. The tool description does not add new parameter-level information beyond what the schema provides. The 'account_id' parameter is mentioned in the schema as well; the description doesn't elaborate further. Baseline score of 3 is appropriate.

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 'Schedule an email for future delivery' with explicit time constraints (min 60 seconds, max 30 days). It distinguishes itself from siblings like 'list_scheduled_emails' and 'cancel_scheduled_email' by mentioning them as related tools, and implies differentiation from 'send_email' by focusing on scheduling.

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?

Provides clear context for when to use the tool (scheduling future emails) and mentions related tools for viewing and canceling schedules. However, it does not explicitly state to use 'send_email' for immediate delivery, which would strengthen guidance.

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