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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description still adds real behavioral value beyond them: prices are read live from the store (freshness/liveness) and the payload includes plan inclusions and refund terms. It stops short of stating currency, tax treatment, or whether responses are cached, which keeps it from a 5.

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?

A single front-loaded sentence that leads with the core payload ('current prices') before the enum-based listing. The mid-sentence enumeration of three product lines is long but each item earns its place by naming a distinct billable service; minor tightening would still help.

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 parameters and full annotation coverage, the remaining burden is describing the return payload, which the description does ('what each plan includes and the refund terms') even though no output schema exists. Gaps remain around currency, billing cadence, and whether prices are per-period — small but relevant for a pricing tool used ahead of start_order.

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 tool takes zero parameters, so the baseline is 4; nothing in the schema needs explaining. The description correctly implies no scoping inputs are required — it returns the full live price list rather than asking for a plan selector.

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?

Specific verb ('read live from the store') plus a precisely enumerated resource: prices for PCI ASV scanning per domain/IP, payment page monitoring, and penetration testing. The resource is distinct enough from check_payment_page and start_order that confusion is unlikely, but the description never names a sibling or states the boundary 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?

Usage is only implied: an agent infers it should call this when it needs price information, likely before start_order. There is no explicit 'use this when', no exclusion, and no mention of the natural companion flow (quotes → ordering) despite start_order sitting among the siblings.

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