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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable context: it places no order and charges nothing, prices via the same server-side path as a real order, and explains that the response includes payment_methods with account vs. x402 options. This goes beyond the annotations and helps the agent understand side effects and response structure.

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 description is well-structured, with the core purpose front-loaded. It is a bit lengthy due to detailed payment method explanation, but every sentence adds value (pricing source, no-order guarantee, payment options). It could be slightly tighter, but the structure is logical and readable.

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 read-only quote tool with 3 parameters and no output schema, the description is comprehensive. It covers purpose, safety, pricing accuracy, and even details the payment_methods response field. An agent has everything needed to correctly invoke it and interpret results, especially given the supporting annotations.

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 input schema has 100% coverage with clear descriptions for each parameter (service_id from search_catalog, quantity, optional service_option_id). The description does not add much beyond the schema, but none is needed because the schema is self-explanatory. It does mention 'quantity bounds enforced' which slightly reinforces the quantity parameter's meaning, but this is minor.

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 clearly states the tool's purpose: 'Get the exact list price to order a service and quantity' and immediately distinguishes it from order placement by noting 'It places no order and charges nothing.' It also contrasts with catalog math, which differentiates it from other catalog-related tools like search_catalog.

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?

The description explicitly instructs to use this tool when an exact price is needed and to trust it over manual calculation from catalog prices. It also specifies that no account is needed and points to alternatives for actual ordering (place_order, place_paid_order) and mentions the REST endpoint for x402. This provides clear usage context and exclusions.

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