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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds valuable non-obvious behavior: the quote is binding, valid for ~30 minutes, and quote_id is required downstream. It also tells the agent not to estimate or adjust prices and to ask the customer to add a service if below minimum order.

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?

Three sentences with no fluff. The main purpose is front-loaded, then the return value and validity are stated, and finally an important constraint on agent behavior. Every sentence earns its place.

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?

Given there is no output schema, the description covers the key return value (quote_id) and its validity period. It also includes the minimum-order handling rule, which is operationally important. It lacks explicit sibling routing, but for a quote-calculation tool with read-only annotations, the essential context is present.

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%, so the description needs to compensate. It explains the conceptual role of postal_code and items by mentioning travel fee, quantity discounts, unit prices, add-ons, and minimum order. It does not cover session_id or per-parameter syntax, but the schema already documents those adequately.

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: 'Calculates a binding quote for one or more services at a postal code'. Lists exactly what is computed (unit prices, quantity discounts, add-ons, travel fee, minimum order) and names a downstream consumer (check_availability), which distinguishes it from sibling tools.

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 provides clear workflow context: calculate_quote produces a quote_id required by check_availability, so the intended position in the booking flow is evident. It also gives an actionable instruction about minimum orders. However, it does not explicitly state when to prefer this tool over prepare_booking or other siblings, nor list exclusions.

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