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

Annotations already cover read-only, idempotent and non-destructive, yet the description adds several non-obvious traits: eventual consistency ('movements may appear about ten seconds after creation'), the required stock:read scope, the specific fields omitted from responses, and API instability without a version bump. These are exactly the behaviors an agent cannot infer from structured fields.

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?

Two dense sentences, front-loaded with the data scope before the caveats, with no filler. It is packed slightly tight – the omission list and caveats share one sentence – but nothing is wasted.

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?

No output schema exists, so the description usefully sketches the return shape (field omissions, ordering, latency) and access requirements. However, it leaves the filtering parameters and the mandatory locationId unexplained, which is a meaningful gap for a six-parameter list tool.

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 only 17% – just the 'after' cursor is documented. The description explains none of the six parameters: it never mentions the required locationId, what the `type` filter accepts, the default/max of `limit`, or how productId vs colourBarItemId narrow results. With such low coverage the description had real room to compensate and does not.

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 names the specific resource (stock changes) and its ordering (oldest first), plus which fields are omitted, so an agent knows exactly what data comes back. The verb is only implied ('Stock changes') rather than stated as a list operation, and the required locationId scope is not mentioned. Sibling confusion is unlikely since all siblings target other resources.

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?

It states a prerequisite ('Requires stock:read') and that this is a preview API that may change, but gives no explicit when-to-use/when-not or alternative tool routing. Usage is only implied by the resource name, which is adequate but thin.

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