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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=false and openWorldHint=true, so the 'WRITE:' label is largely redundant. The SKU-matching constraint is genuinely useful domain context, but the description says nothing about duplicate-SKU failure behavior, permissions, or side effects — a notable gap given idempotentHint=false.

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 fragments, front-loaded with the WRITE marker and the most important constraint. Nothing is padded.

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 10-parameter, destructive, non-idempotent mutation with nested metadata/variation_list objects and no output schema, the description is far too thin. It never explains what the nested objects are for or what happens on a duplicate SKU.

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 60%, with price, metadata, variation_list and manufacturer_sku carrying no descriptions. The description adds real meaning for 'code' ('must match the code your orders arrive with') beyond the schema's 'Unique SKU.', but leaves the other undocumented parameters unexplained.

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+resource ('add an inventory item') and prefixes it with 'WRITE:', which cleanly separates it from the read siblings (get_inventory_item, list_inventory_items). It does not explicitly name create-vs-update alternatives, but the intent is unmistakable.

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 only usage-like statement is the SKU constraint, not when-to-use guidance. There is no mention of when to call this versus orderdesk_update_inventory_item, nor what to do if the SKU already exists.

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