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

Annotations already declare readOnly, idempotent and non-destructive, so 'Makes no changes' is largely redundant. What the description adds beyond structured data is the precondition (live/claimed businesses only) and a preview of the returned payload — snippet types, CSP entries, placement notes, verification steps — which is valuable since there is no output schema.

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?

Three dense sentences, front-loaded with purpose then payload contents then the precondition. Every clause carries information an agent would otherwise have to discover by trial, and there is no filler.

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?

With no output schema, the description usefully enumerates what is returned and states the live-business precondition, which is enough to call it correctly. It does not cover failure behavior for an invalid identifier, keeping it just short of complete.

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% and the single parameter's description already spells out Amfion address, connected domain or short name. The description restates the same three forms without adding format, validation or default details, so the baseline 3 applies.

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 ('Returns website installation code') scoped to 'an existing live Amfion business' and enumerates the accepted identifiers. The 'Unclaimed previews are unsupported' clause implicitly separates it from the sibling preview tools, so an agent can route without 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 a clear precondition (business must be existing and live) and an explicit exclusion (unclaimed previews are not supported), which is real when-to-use guidance. It stops short of naming an alternative tool for the preview case, so it earns a 4 rather than a 5.

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