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

Annotations already declare that this is a non-read-only, non-destructive, non-idempotent, closed-world operation. The description adds useful behavior: it creates a git repository, defaults the template to 'blank', returns clone_url, requires a repo key from create_api_key for cloning, and clarifies that creation does not publish.

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?

The description is three dense sentences with no wasted wording. The core action and key caveat are front-loaded, and the follow-on Git cloning detail is placed after the primary behavior.

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 a creation tool with annotations and no output schema, the description covers the essential context: what is created, where projectId comes from, the template default, what is returned, how to clone the repo, and the important non-publication limitation.

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 67%, and the description compensates for the undocumented projectId parameter by specifying that it comes from list_projects. It also reinforces the name purpose and template default beyond the schema descriptions.

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?

The description gives a specific verb and resource: create a site, and expands it to include the git repository forked from a starter template. It distinguishes the operation from publishing by stating that creating a site does not publish it, so an agent can tell this apart from publish_site.

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?

It states the prerequisite for projectId ('from list_projects') and gives a clear exclusion ('does not publish it'). It does not explicitly route between create_site and sibling creation tools such as create_project or create_site_page, but the operational context is clear.

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