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

No annotations exist, so description carries full burden. Clearly states return value (order_id with pipe suffix), weight unit (grams), optional COD behavior, default shipping method. Discloses that ID needs full value passed to other tools. Lacks info on error modes, idempotency, or whether order is created immediately.

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 concise sentences front-load key details. No fluff or repetition. Could potentially combine first two sentences, but remains tight. Missing punctuation is minor.

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 creation tool with 9 params, nested objects, no output schema, and no annotations, description covers essential defaults and return format but omits many usage patterns: what happens on failure, required permissions, idempotency, relationship to check_duplicate or update_order_status. Barely adequate for reliable invocation.

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 78% – already detailed in schema. Description adds critical context for weight ('in GRAMS'), shipping_method defaults, and cod_amount purpose. Explains order_id return format. However, some params like remarks still lack schema description and description doesn't compensate.

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?

Description clearly states 'Create a shipment order' with specific verb and resource. Distinguishes from siblings like cancel_order, get_order, list_orders by focusing on creation. Somewhat vague on exact scope (creates only? returns immediately?). Could clarify if it's async or synchronous.

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 states default shipping method (Thailand Post EPS) and provides alternative ('thaipost requires contract'). Hints at prerequisites by referencing list_shops for shop_id. Could add more when-to-use vs cancel/update tools, but context is reasonable.

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