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

Even with annotations already marking the operation as non-read-only, destructive, and idempotent, the description adds substantial behavioral detail: variant preservation rules, refusal instead of silent fallback, conflict behavior on concurrent changes, no-op idempotency, and conditions that block the upgrade. It also explicitly states when the thing is not changed.

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?

The description is long but dense, front-loading the core purpose and then walking through edge cases in a logical order. The final catalog and 'front door' navigation sentence is only loosely related to the tool itself, which prevents a perfect score.

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?

There is no output schema, and the description does not state the success return value, but it covers the invocation requirements, variant selection, conflict handling, retry behavior, and blocking conditions comprehensively. The missing return shape is a minor gap given how much operational context is provided.

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?

The description greatly enriches the drawing_variant_name parameter's meaning by explaining what happens when the exact variant is absent, how null selects the base, and how retries behave with the requested selection. thing_id needs no further explanation beyond its name and the 'thing' context, and the schema already constrains its type and range.

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 opens with a specific action and resource: as owner, adopt a typed active thing's latest kind revision. This clearly distinguishes upgrading a thing from generic editing (thing_edit) or revising kinds (revise_kind) without needing to inspect 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?

The description gives explicit context for when the tool applies (owner, typed, active, latest revision) and states exclusions: untyped things and things with open sale offers cannot be upgraded. It does not name a specific sibling as the alternative for the excluded cases, so it falls just short of a 5.

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