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

Annotations already flag this as a non-read-only, destructive, non-idempotent, open-world mutation. On top of that the description discloses that the operation is asynchronous and must be polled, that source edits may run in preview, and that corrections reuse the original sessionId. That is substantial behavior beyond the structured hints.

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?

Purpose and scope are front-loaded, then prerequisites, then lifecycle, then the publish caveat — a sensible ordering. It is on the long side, and the closing sentence about the Replo agent using its normal tools is contextually useful but the least load-bearing.

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, destructive, multi-session operation with no output schema, the description covers everything an agent needs: prerequisite brand kit and site state, how to start, how to poll, how to correct, and that publishing is a separate step.

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 adds operational meaning the schema only implies: that omitting sessionId starts an operation, that a correction pass must target the same unchanged site, and that the agent implements via its own tools and integrations. Modest but real value above the schema text.

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?

Opens with a specific verb (apply) plus a precise resource set (shared style tokens, fonts, layout, shared components) scoped to a single site's drafts. It explicitly contrasts itself with the saved brand kit, so an agent can separate it from create_or_update_brand_kit and get_brand_kit without reading either schema.

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?

States the prerequisite (provisioned site, and create_or_update_brand_kit first if no saved brand), the follow-up (poll get_agent_session), the continuation path (same tool with sessionId and unchanged target), and the exclusion (publish_site separately to go public). This is a full when/when-not/alternative map.

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