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

Annotations already declare idempotentHint=true and destructiveHint=false, but the description adds the concrete mechanism: the shop returns the original order rather than creating a duplicate on retry. It also documents the user-confirmation prerequisite and the return shape (id, status, total), which the annotations cannot convey.

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 tight sentences: the action, then the retry/idempotency rule, then the confirmation prerequisite and return values. No filler, and the core purpose is front-loaded.

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 3-parameter mutation with no output schema, the description covers the required inputs' operational context (idempotency retry behavior, user confirmation) and states the return fields, so an agent has everything needed to invoke it correctly.

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 coverage is 100%, so the baseline is 3, but the description goes further by explaining the consequence of reusing idempotencyKey (original order returned) and the human-confirmation requirement tied to productId/quantity. It adds meaning beyond the field-level schema text rather than merely restating it.

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 ('Place an order for one product') and scopes it to a single product, which cleanly separates it from cancel_order, get_product, and search_products. An agent can identify the operation without opening the schema.

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?

Explicitly says to confirm product and quantity with the user before calling, and gives the retry condition for reusing the idempotency key instead of generating a new one. The when-to-use and retry-alternative conditions are both stated rather than implied.

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