Postpone a session

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

The annotations already state this is a non-read-only, non-idempotent, non-destructive mutation. The description adds genuinely new behavioral context: confirmation is handled server-side, and invalid moves fail with an explanatory result rather than silently succeeding. It stops short of describing other side effects (such as notifying participants), which is the only remaining gap.

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 core action is front-loaded in the first sentence, and the second paragraph lists the rejection conditions compactly. The confirmation instruction is slightly repetitive ('after the user confirms it' followed by 'do not ask for a confirmation'), but every sentence carries actionable content.

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?

An output schema exists, so return-value detail is not required, yet the description still notes that failures explain themselves. For a three-parameter mutation, the action, preconditions, confirmation flow, and failure behavior are all covered.

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 100%, so the baseline is 3. The description still adds meaning by explaining the role of `as_of` as the validation reference point for both the session's original start and the proposed new date, which goes beyond the schema's terse 'reference date of the call.'

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 names a specific verb and resource: 'Move the start date of one training session.' That is unmistakably distinct from sibling tools such as cancel_enrollment or session_detail, which handle cancellation and retrieval rather than rescheduling.

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?

It gives a clear precondition for use (the date change happens after the user confirms) and explicit exclusions: sessions that are completed, cancelled, or that started before `as_of` cannot be moved, nor can they be moved to a date before `as_of`. It also tells the agent not to request confirmation itself, which is unusual and useful procedural guidance.

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