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

Annotations only give a generic mutation profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false). The description adds real substance: Stripe is charged, the session completes, and the no-instrument path returns requires_escalation with continue_url plus a concrete AED 49.50 fee. It still omits that the call is non-idempotent and that an idempotency-key should be supplied for a payment operation.

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 sentences, front-loaded with the action and its side effect, and no filler. The second sentence is a long compound clause, but each detail (charge, escalation, fee) is load-bearing.

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 payment-completing mutation with nested parameters and 0% schema coverage, the description covers behavior well and an output schema exists so return values need not be detailed. However, the required id and idempotency-key are left entirely unaddressed, which is a meaningful gap for a non-idempotent charge operation.

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 0% across three parameters, including nested objects, so the description must carry the load. It only loosely gestures at the payment parameter ('tokenised payment instrument') and says nothing about the required checkout id or the meta.idempotency-key field, leaving most parameters unexplained.

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 ('Complete a UCP checkout') and goes on to say exactly what completing it does: places table requests with Dubai Table. That outcome-oriented framing separates it from create_checkout/update_checkout without needing to name them.

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?

Describes the two operative conditions clearly (with vs without a tokenised payment instrument) and what each path yields, which tells the agent when the escalation branch applies. It never explicitly says when to prefer this over create_checkout or update_checkout, so it falls short of the 5 bar.

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