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

Annotations provide idempotentHint. Description adds behavioral detail: 'no rebuild', 'dest keeps its slug, domains, and access settings; only the served bytes change.' This goes beyond schema and annotations, though auth needs or rate limits are omitted.

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?

Description is two sentences, front-loaded with the key action and details, with zero waste. Every sentence adds value.

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?

Given the tool's simplicity (2 params, no nested objects, presence of output schema), the description covers all essential aspects: what is copied, what remains unchanged, and the no-rebuild property. No gaps remain.

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 has 0% description coverage, but description clarifies srcSlug as 'your preview' and destSlug as 'your production site / custom domain', adding semantic meaning to the otherwise bare 'string' type.

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?

Description clearly states the action (copy exact live bytes), the resources (owned sites: srcSlug preview and destSlug production), and the outcome (no rebuild). It distinguishes from siblings like publish_site by emphasizing exact byte copy without rebuild.

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?

Description implies usage for promoting a preview to production without rebuild. It does not explicitly state when not to use or mention alternatives (e.g., publish_site), but the context of 'preview to production' is clear enough for an agent.

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