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

Annotations cover the safety profile (destructiveHint=true, readOnlyHint=false, idempotentHint=false), but the description adds meaningful context beyond them: the 'Allow changes' permission requirement, dry_run's validate-only behavior, the idempotency_key retry guarantee, and the return shape/time error format. It does not address side-effect scope or rate limits, so just short of top marks.

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?

Four dense sentences that are front-loaded with the core operation before constraints and parameters. Efficient overall, though the parameter clause at the end reads as a compressed list that could be structured more cleanly.

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 5-param, nested-body, mutating call with no output schema, the description covers return format, required permission, dry-run safety, and retry semantics. Completeness is strong; only exhaustive side-effect/error handling detail is absent.

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 all five parameters are already documented in the schema. The description restates dry_run and idempotency_key semantics that largely duplicate the schema text, adding only minor framing; baseline 3 is appropriate.

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 ('Creates or changes data through a SKU.io REST API endpoint') with the HTTP methods enumerated. It clearly distinguishes itself from the read sibling (api_read) and ties operation to search_api as the discovery mechanism, so an agent can tell it apart 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 bounds usage: only reviewed endpoints that create records or edit fields are callable, deletes/voids/cancels/sends are unavailable, and search_api marks callable endpoints. This gives both when-to-use and when-not, plus a routing alternative.

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