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

Annotations only declare openWorldHint=false and destructiveHint=false, so the description carries the real burden and does: human-in-the-loop latency, push delivery, is_simulation_available behavior change, minutes-long expiry, and single-use consumption. These are exactly the traits an agent could not infer from the schema.

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 mechanism first, then the workflow, then the simulation exception and lifetime constraints. No filler sentences, but the workflow is delivered as one long chained sentence that a numbered sequence would make easier to scan.

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 6-param, nested-object, output-schema-bearing tool this covers the workflow, prerequisites, expiry, single-use semantics, and the simulation branch, so no return-value explanation is needed. The remaining gap is guidance on the origin and description parameters that an agent must still supply.

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 only 17% across 6 params, so the description must compensate. It meaningfully constrains actionType and actionPayload ('the exact action_type and payload the tool documents') and implies the session id return, but says nothing about originLocation, originPlatform, actionDescription, or the originTrustedDeviceId wrapper, leaving four parameters opaque.

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 (opens) and resource (a sensitive-action approval session) and immediately describes the mechanism: a push notification to the user's trusted device. It is clearly distinguishable from the sibling approval_session_get_approval_session_status, which it names as the polling counterpart.

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?

Gives explicit when-to-use triggers (before the domain auth-code reveal, trademark firm handoff, ITIN submit), the full call sequence (create, tell user to check phone, poll status until APPROVED, pass session id to the gated tool), and a fork for the simulation case where no push is sent.

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