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

Annotations only declare it is a non-read-only, non-idempotent, open-world write; the description goes further and discloses the whole behavioral arc: no password/card required, an emailed set-password link, widget activation gated on sign-in (email confirmation), and leads retained until a card is added. That is exactly the context annotations cannot carry.

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-loaded with the action and the return values, then the free/trial economics, then the eligibility constraint. It is dense but every clause carries a distinct fact; the pricing parenthetical is slightly incidental but not wasteful.

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 still names what is returned, covers the multi-step onboarding that follows the call, and states the eligibility gate before an agent commits to an irreversible, non-idempotent write. Nothing needed to call it correctly 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?

Schema description coverage is 100%, so the schema already documents all six parameters and their optionality. The description adds only the accepted-email constraint tied to owner_email and the real-business-email requirement; it does not explain the trade taxonomy or service_area format, so the baseline 3 is appropriate.

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+resource ('Creates a contractor account') and immediately names the artifacts returned (widget token and embed tag), routing the agent to the sibling get_install_snippet. It is clearly distinguishable from estimate_cost, get_pricing, or list_trades.

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?

Explicit when-to-use and when-not: only when the person owns the business or asked for the setup, with their real business email, and it refuses test/disposable/placeholder addresses. That is a concrete selection condition and a hard exclusion, not implied guidance.

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