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

Annotations already flag destructiveHint, openWorldHint, and non-idempotent, but the description adds beyond them: the operation is asynchronous and must be polled with get_agent_session, edits may execute in the site's preview, and corrections reuse the same sessionId with an unchanged target. That is exactly the operational context the hints cannot convey.

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, side-effect scope, prerequisite, and alternatives are front-loaded in the first few sentences. A couple of sentences (the Replo agent description, the publish_site reminder) are supportive rather than essential, keeping it just under maximum density.

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?

Without an output schema, the description still tells the agent what to expect (an internal-agent session to poll via get_agent_session) and how to continue or correct a run. For a destructive, async, three-parameter tool this covers everything needed to invoke it safely.

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, and the description earns a bump by framing sessionId in the real correction workflow ('call this same tool with its sessionId and unchanged target'), reinforcing the mismatch-rejection behavior. It adds little about 'instructions' beyond the schema, so it stays short of a 5.

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 with concrete scope: it copies the saved brand onto the selected site's shared style tokens, fonts, layout, and shared components. It explicitly clarifies it 'Affects that site's drafts, not the saved brand kit', which separates it from update_brand and publish_site without the agent opening 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?

Gives explicit prerequisites ('Use update_brand first if there is no saved brand', 'Requires a provisioned site'), names the follow-up tool (publish_site) with a when-to-use condition, and describes the correction path via sessionId. Little 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.