Move twin time forward

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

Annotations already declare non-read-only, open-world, non-idempotent and non-destructive, but the description adds genuinely new behavior: events occur at their own scheduled times, resulting webhooks are delivered synchronously before the call returns, and the response reports the new time and event count. It does not mention permission requirements or how long a large advance might take, but the side-effect ordering disclosure is the key value.

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, no filler, with the side-effect ordering front-loaded before the return value. The second sentence is a long semicolon chain that packs three distinct points together, which slightly hurts scannability but nothing is wasted.

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?

There is no output schema, and the description compensates by stating what is returned (new twin time and scenario event count). Combined with the side-effect timing and the 0-minute rule, an agent has everything it needs to call this correctly for a single-parameter tool.

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% and already documents the 'up to ten years' bound, so the baseline is 3. The description earns a point by explaining the semantics of the 0 value (flush already-due deliveries), which the schema does not say.

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 that twin time is advanced and that scheduled scenario events fire along the way, which is a specific verb+resource. It is slightly narrative ('Twin time stands still until you move it') rather than a direct 'Advances the twin clock by N minutes', but an agent can still tell exactly what it does and how it differs from siblings like twin_status or twin_rewind.

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 clear context for use (advance time so scheduled events and their webhooks fire) and explicitly defines the edge case '0 minutes only sends deliveries already due', which is the main ambiguity an agent would face. It does not name an alternative or an exclusion (e.g. relative to twin_rewind), so it falls short of a 5.

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