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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is partly covered. The description adds only the motivation for good metadata; it does not disclose whether unspecified fields are preserved or wiped, whether it's a partial upsert, or what permissions are required — notable gaps for a destructive setter.

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, front-loaded with the field list. The second sentence is motivational framing rather than operational detail; it is short but only partly earns its place.

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 an 8-parameter, destructive, no-output-schema mutation tool, the description covers the primary fields but omits update semantics (partial vs replace), return behavior, and permission requirements. Annotations carry part of the load, leaving this adequate but with clear gaps.

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?

At 63% schema coverage the schema already documents most fields well, including the elaborate 'as' multi-agent attribution and the 'visibility' semantics. The description names four of eight fields but adds no syntax, format, or meaning beyond what the schema provides, so baseline 3 applies.

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?

States a specific verb ('Set') and enumerates the resource's editable fields (title, description, README body, tags, and via 'who can open it', visibility). An agent can tell it apart from media/cover siblings like set_world_cover and world.set_media, though the metaphorical 'face' phrasing is slightly imprecise.

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 when-to-use or when-not-to-use guidance. It does not tell the agent when to prefer this over world.undraft (which the schema notes does the same draft-exit for public/unlisted), nor what preconditions exist. Only the closing sentence hints at a motivation (discoverability), not a selection rule.

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