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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent mutation. The description adds useful behavior beyond that: the item is created, and stocked=false items never check or deplete inventory. It does not cover duplicate-SKU behavior or permissions.

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 short and front-loaded with the core action. 'Effects: item created' is slightly redundant with the opening verb, but otherwise the structure is efficient.

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 6-parameter creation mutation, the description covers purpose and stocked behavior but is silent on duplicate SKU handling, whether the SKU is immutable, permissions, and what is returned. With no output schema, those gaps leave the definition only minimally complete.

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 schema already documents all six parameters. The description adds some operational meaning for stocked=false, but it largely overlaps the schema's existing 'False for services — never depletes' wording and adds no detail for sku, name, on_hand, unit_price, or tax_rate_bp.

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 states a specific verb and resource: 'Create a sellable item.' No sibling tool creates sellable items, so the action is unambiguous against core_create_customer, core_set_price, and the inventory 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?

Usage is implied by the purpose, and the stocked=false guidance helps distinguish item types. However, the description does not explicitly say when to use this versus alternatives like core_receive_stock, core_set_price, or inv_set_opening_cost.

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