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

Annotations already indicate destructive and idempotent behavior, and the description adds valuable detail: all files are replaced, the URL and expiry are preserved, and omitted settings remain unchanged. This gives the agent a clear model of side effects with no contradiction against the 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?

Two information-dense sentences contain the action, constraints, preserved invariants, and required credential without filler. The most important behavior is front-loaded.

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 6-parameter mutation with annotations and an output schema, the description covers prerequisites, scope, side effects, and preservation semantics. The only notable gap is that the schema requires files even for settings-only changes, and the description's 'Replace all files or change settings' phrasing could mislead an agent into thinking files are optional for a settings-only update.

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, but the description adds meaningful parameter context: update_token provenance, the semantics of omitted optional settings, and that files are a full replacement set. It does not enumerate enum values, but the schema already covers those.

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 precise operations: replace all files or change access/mock-form settings on an unclaimed anonymous website preview. It also names preserved invariants (randomized URL and 24-hour expiry), clearly distinguishing this tool from website_preview_create and website_preview_status.

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?

The description makes the prerequisite explicit: the agent must have the opaque update token returned by website_preview_create. It does not enumerate exclusions versus siblings, but the unclaimed-preview scope and token requirement provide enough context for correct selection.

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