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

Annotations only declare readOnlyHint=false, so the description carries the full burden and does: the TWO-STEP preview/commit contract, the confirmationToken returned by the preview, the requirement to show the preview to the user before writing, and the auth constraint ("a workspace API token cannot write", OAuth required). It also discloses what the preview resolves (account, marketplaces, ASINs against the catalog) and that mistyped ASINs surface there.

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 purpose, then granularity, then the two-step flow, then the type vocabulary — a sensible order for a dense tool. It is long, and the sentence enumerating `type` values duplicates the schema enum descriptions nearly verbatim, which is the one passage that does not earn its space.

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, and the description compensates by describing what the preview returns (resolved account/marketplaces/ASINs plus a confirmationToken) and what the commit call requires. For a mutating, two-phase tool with auth constraints, an agent has everything needed to call it correctly and safely.

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 baseline is 3; the description adds genuine semantics the schema does not, namely the grouping rule for the `events` array (one call, multiple entries, max 50) and the purpose of the two-step commit/confirmationToken pair. The per-`type` vocabulary is largely a restatement of the enum descriptions in the schema, which keeps it from a 5.

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 ("Log one or several EVENTS on Nova") and immediately grounds it with a concrete metaphor ("dated notes drawn on the charts so a later movement can be explained") plus four real-world examples. An agent can distinguish this from list_events or explain_movement without opening any 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?

Explicit routing: "Check list_events first when the seller may already have logged it" names the sibling and the condition. It also prescribes the trigger ("the seller tells you what they did") and the granularity rule (same change across many ASINs = one event; different day/type/description = separate entries), which is exactly the decision an agent would otherwise get wrong.

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