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

Annotations already declare destructiveHint=true and idempotentHint=true, and the description reinforces this with "Overwrites the current quantity" plus the write_products permission requirement and the concrete endpoint. It stops short of describing the response body or error modes, which keeps it from a 5.

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?

Front-loaded with the "WRITE" marker and the core operation, then the alternative, then the auth and endpoint. No sentence is wasted and nothing important is buried.

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 three-parameter, two-required write tool with no output schema, the description covers action, scope, defaulting, auth, and the destructive overwrite semantics. The only gap is what the call returns, which is minor since no output schema is promised.

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 100%, so quantity bounds, variant_id, and the primary-location default are all documented in the schema. The description repeats the location default and the 0-or-more bound but adds no format or semantic detail beyond that, so baseline 3 applies.

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 with exact scope: "Set the stock of one variant at one location to an exact number." The leading "WRITE" marker plus the contrast with the sibling adjust tool makes it unambiguous 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 names the alternative ("use easystore_adjust_inventory_level for a relative change") and the condition that selects it, plus the location_id omission behavior. An agent can route correctly from this sentence alone.

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