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

Beyond the annotations it discloses the ownership side effect (recipient is added as owner first), the rate limit of 5 per business per hour, the 24-hour dedupe window, and that clicking the link sets ownerSignedInAt. It also explains idempotencyKey semantics for deliberate repeats, which is exactly the kind of behavioral detail annotations alone cannot convey.

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 action and its optional status are front-loaded, and the rate-limit/dedupe caveats are grouped at the end where they belong. The 'Step 12:' prefix is context the agent may not have and adds little on its own, and the idempotency sentence restates the schema description.

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 three-parameter mutation with no output schema, the description covers the effects (owner granted, email sent, ownerSignedInAt on click), limits, and idempotency behavior. It doesn't say what the call returns on success, which is the only notable gap given the absent output schema.

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?

The description adds meaning not in the schema by giving the email parameter a default (ownerEmail) and by framing idempotencyKey as the lever for deliberately repeating the action versus safe retries. businessId is left to the schema's own description, so coverage is good but not fully compensated in the prose.

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 states a concrete action: emails a sign-in link bound to the business, and first adds the recipient as owner. That is a specific verb plus resource an agent can act on. It doesn't explicitly contrast with a named sibling (e.g., complete_onboarding or create_api_key), so it falls short of a 5.

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 gives explicit when-not guidance: 'Nothing in setup needs it' and the agent can keep running the line, with the human able to take over by clicking the link. That is clear context for skipping the call. It stops short of naming alternatives or stating the condition under which an agent should proactively send the invite.

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