Schedule an email

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

Annotations already disclose readOnlyHint=false, idempotentHint=false, and openWorldHint=true, so the safety profile is established. The description adds one genuinely new behavioral detail — delivery can happen on 'local or Exchange-side' — which is useful context. However, it does not disclose the open-world side effects implied by openWorldHint=true or clarify that repeated calls create duplicate scheduled emails given idempotentHint=false. No contradiction with annotations.

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?

A single front-loaded sentence with no waste. The core scheduling action leads, and the local/Exchange-side distinction follows. It is appropriately short 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 8 parameters with full schema coverage and an existing output schema, the description covers the essential scheduling intent. However, as a mutation tool with openWorldHint=true, it omits behavior an agent would benefit from knowing, such as whether scheduling creates a persistent entry visible in list_scheduled, or any limits on how far in advance delivery can be set. Adequate but not complete.

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 all eight parameters are documented in the input schema itself. The description adds no parameter-level meaning beyond what the schema provides, so the baseline of 3 applies — the schema does the heavy lifting and the description neither helps nor hurts.

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 states a clear action — freeze an email now and schedule delivery later — which distinguishes it from immediate-send tools like send_email and draft tools like create_draft. The verb 'schedule' plus the delivery timing is specific enough to identify the tool's resource and behavior, though 'freeze an email now' is slightly creative and could confuse on first read.

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?

No explicit guidance is given on when to use this tool versus alternatives. The 'local or Exchange-side delivery' phrasing implies delayed delivery rather than immediate, and the sibling send_email exists, but the description never states 'use this for future delivery, send_email for immediate.' An agent must infer the usage context.

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