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

Annotations already cover the safety profile (readOnly=false, destructive=false, idempotent=false, openWorld=true). The description adds meaningful context beyond them: the 30-day full-widget window, the included first scan, the return fields (site id and plan tier), and the account requirement.

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?

Front-loads the core action, then workflow guidance, then the prerequisite. Every sentence contributes, though the parenthetical about self-signup is slightly tangential.

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?

No output schema, but the description names the return values (site id and plan tier) and the follow-up tools, plus the account prerequisite. It covers what an agent needs to invoke and chain this correctly, missing only edge cases like duplicate-domain handling.

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 description coverage is 100%, so the schema carries the parameter documentation burden. The description adds no parameter-specific syntax or constraints beyond what the schema already states, which is the baseline 3.

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: "Add a website to the signed-in WebAbility account." It clearly distinguishes itself from siblings like list_sites and get_install_snippet, so an agent can tell what it does without opening the 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?

Provides explicit next-step routing ("put the get_install_snippet tag on the site, and use create_upgrade_link to get a payment link for the WebAbility Pro plan") and a prerequisite (needs a free account). It names related tools but does not state when-not to use this tool, so it stops short of full when/when-not coverage.

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