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

Annotations already supply readOnlyHint=false, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds useful behavioral context beyond annotations: 'Affects all connected clients' indicates a global-side-effect, and it reveals the underlying API call. It doesn't contradict 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?

Four short sentences, each earning its place: operation, constraint, alternative, and side-effect. The main purpose is front-loaded, and there is no filler or repetition of annotations.

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?

For a single-parameter setter with no output schema, this is complete. It explains what the value means, the valid range, the sibling tool for relative changes, and the impact on all clients. Nothing an agent needs to invoke it correctly is missing.

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 schema already documents worldTime as an absolute number >= 0. The description adds meaning by clarifying 'seconds since the world epoch', which specifies the reference frame, and reinforces the absolute-vs-relative distinction. This adds value over the bare 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?

The description states a specific verb and resource: 'Set the in-world clock to an ABSOLUTE value in seconds since the world epoch.' It also names the underlying game.time.set function and explicitly distinguishes itself from the sibling world-time-advance, leaving no ambiguity about what the tool does.

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 explicit when-to-use and when-not-to-use guidance: 'To make a relative change use world-time-advance instead.' This directly tells an agent that this tool is for absolute values only and routes to the correct alternative, which is exactly what usage guidelines should do.

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