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

Annotations already declare destructiveHint=true and openWorldHint=true, and the description adds real context beyond them: the operation is asynchronous, must be polled via get_agent_session, and source edits may execute in the preview. It does not spell out what specifically gets destroyed or how to interpret a failed session, so it stops just short of the top score.

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?

The scope statement is front-loaded and the sentences are dense with actionable facts. The one weaker sentence ('The Replo agent uses its normal tools and connected integrations...') is explanatory rather than essential, keeping it shy of 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?

For an async, non-idempotent mutation with a fully documented 3-parameter schema and no output schema, the description covers prerequisite, async polling target, preview side effects, correction flow, and the publish handoff. An agent has everything needed to invoke and follow up correctly.

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; the description earns a step up by explaining the sessionId continuation workflow ('For corrections, call this same tool with its sessionId and unchanged target'), which ties the parameter to a concrete correction scenario rather than just restating it.

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 plus the exact resource and scope: 'Update site-wide SEO title, description, social preview, favicon references, or search visibility in the selected site's root layout.' It also explicitly carves itself away from the nearest sibling with 'Does not rename the dashboard label,' which separates it from update_site.

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 explicit when-to-use (SEO/social/favicon/visibility edits), when-to-use-something-else ('Use publish_site separately to make changes public'), a prerequisite ('Requires a provisioned site'), and a correction path via the same tool with sessionId. Nothing about routing is left to inference.

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