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

Annotations already declare readOnlyHint=false, destructiveHint=false and idempotentHint=false, so the safety profile is covered structurally. The description adds real context beyond that: the connection-scope requirement, the provisioning side effect (starter page), and the resulting public URL. It does not state what happens on a duplicate/non-idempotent repeat call, which is the one notable gap.

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 short sentences, no filler, and the core action is front-loaded ahead of naming rules and the availability constraint. Every sentence carries distinct, actionable information.

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 single-parameter creation tool with no output schema, the description supplies everything needed to call it correctly: the effect, the naming contract, the resulting URL, and the gating precondition. Nothing material is missing.

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?

With 100% schema coverage the baseline is 3, but the description earns more by adding naming constraints the schema omits: lowercase letters, numbers and hyphens, 3 to 40 characters, plus the derived URL form. Those constraints directly determine whether a caller-supplied name is valid.

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 names a specific verb and resource ("Creates a new site") and adds the concrete side effect an agent needs: a starter page is provisioned and the site is live at https://<name>.pagehaus.site/. It is unmistakably distinct from siblings like list_sites or add_custom_domain.

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 an explicit applicability precondition — "Only available when the connection covers all sites" — which tells the agent when the call will succeed. It does not name an alternative tool or a when-not-to-use case, so it stops short of the top score.

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