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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description adds genuinely new behavioral facts: the call blocks for up to 45 seconds and returns a non-terminal still_waiting status instead of failing. It does not state whether waiting can time out permanently or what happens on the approval side after repeated polls.

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?

Two tight sentences, zero filler, with the blocking constraint and the non-approval outcome front-loaded. Nothing could be removed without losing 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?

No output schema exists, so the description must describe return values, and it only names the still_waiting case. An agent still does not know the success payload or what to do after a still_waiting result on a read-only, open-world polling tool.

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 only 33%: api_key is documented in the schema, but session_id is undocumented in both schema and description, and timeout_seconds is only implied by the '45s per call' phrasing. The description partially compensates by tying the wait window to the timeout cap but adds no meaning for the required session_id.

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 (wait) plus the exact external condition (PayPal reports user approval) and the polling window. This is clearly the polling/waiting tool among siblings such as complete_checkout and request_paypal_payment, though it never names an alternative explicitly.

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?

'Wait (up to 45s per call)' and the still_waiting return value imply a retry loop, which is useful context, but it does not say when to call this versus complete_checkout, nor whether to re-invoke after a still_waiting result. Usage is inferable rather than stated.

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