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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: pricing excludes shipping and coupons, and no stock is reserved, which tells the agent the estimate is non-binding.

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 short sentences, zero filler, with the core action front-loaded and the caveats trailing. Every clause carries 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?

For a simple read-only tool this is close, but with no output schema the description should say what an estimate returns (per-item prices, totals, currency). The absence of any return-value hint leaves a real gap.

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%, but the single 'items' parameter is structurally self-explanatory (product_id + quantity, 1-10 items, quantity 1-1000). The description adds the notion that pricing is quantity-dependent ('current quantity prices') but does not explain the items array or the 10-item cap.

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: 'Estimate products at current quantity prices.' An agent can tell this is a pricing/quote operation rather than a cart mutation, though it never names the sibling it differs from (prepare_cart).

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. The clauses 'Excludes shipping and coupons, reserves no stock' hint that this is a non-committal pre-check versus prepare_cart, but the description never explicitly says when to use this instead of prepare_cart or search_products.

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