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

Well beyond the read-only/idempotent annotations: it discloses the 60-minute link lifetime, that screenshots are disabled (screenshot_status is disabled), no-login access, temporary single-version access scope, and that default visitor audience omits speaker notes. It also caps expectations honestly by stating device emulation does not verify real phones, WeChat, or cross-device control.

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?

Front-loaded with purpose and the returned artifact, and nearly every sentence earns its place by adding behavioral constraints. The trailing keyword block is somewhat boilerplate filler, which keeps it from a 5.

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?

No output schema exists, so the description must describe the return value, and it does (interactive_url, 60-minute validity, no images returned). Combined with the lifetime, access, and audience caveats, an agent has everything needed to call it and hand off the result.

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 0% across 7 parameters, so the description carries the load. It does add real meaning for audience ('Default visitor audience never includes speaker notes') and viewports (switching and side-by-side comparison), but page, panel, theme, and wait_ms are never explained, leaving most of the parameter surface undocumented.

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 and resource: returns an interactive preview link (interactive_url) into the real SPACE viewer for a given version. The negative list (does not publish, record visits, submit feedback, edit access, join live rooms) cleanly separates it from publish_version and the set_* siblings.

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?

Gives a clear directive on what to do with the result ('hand interactive_url to the requesting user') and a caution ('share only with the requesting user'). It stops short of naming a specific alternative sibling (e.g., preview_downloads or read_version) and the condition that would select it, so it is strong context rather than full when/when-not routing.

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