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

Annotations already cover the read-only/non-destructive/closed-world profile, and the description adds real context beyond them: the tool works before the user signs in (an auth constraint agents would otherwise have to discover) and it describes the shape of the returned detail. It stops short of noting size or rate limits, so it earns a 4 rather than 5.

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 sentences, each doing distinct work: trigger, return contents, and prerequisites/next step. The scoping and auth facts are front-loaded 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?

An output schema exists so return-value documentation is unnecessary, and the remaining agent questions — when to call it, where the slug comes from, whether login is required, and what to do next — are all answered.

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 is documented as "A template slug from list-templates"; the description repeats the same provenance without adding format or validation detail. Baseline 3 is correct when the schema already carries the semantics.

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 resource (one WebTwizz template) and enumerates exactly what a caller gets: purpose, pages, large picture, and a live demo link. It also implicitly contrasts with list-templates by taking its output as input, so the agent can separate the two 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?

"Use this when the user wants a closer look at one template" gives a concrete trigger, "Takes a slug from list-templates" gives the prerequisite, and "create-site with the slug as template starts a site from it" names the alternative path. When-to-use, input source, and next step are all explicit.

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