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

Annotations already declare destructiveHint=true, and the description adds substantial operational detail beyond that: delete removes the version and its tags, running sandboxes are unaffected, and an image still needed by an App is refused with image_in_use. It also clarifies tag movement/removal and list-versus-get log behavior.

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 front-loaded with the overall scope, then compact action-specific clauses. Every sentence carries operational information, and there is no filler despite covering four actions and ten parameters.

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 complex four-action, destructive tool with no output schema, the description provides list/get return shape, pagination behavior, deletion effects, and a key error case. It does not describe tag/delete return values or every optional parameter in detail, but it is sufficient for an agent to invoke the tool correctly.

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?

With only 40% schema description coverage, the description compensates well by spelling out action signatures and explaining cursor back-passing, tag movement and removal, and logsAfter as build-log lines. It still leaves state filtering and some optional parameter semantics implicit, so it is not fully exhaustive.

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 states specific actions (list, read/get, tag, delete) on a specific resource (images sandboxes start from), and explicitly names runtime_images_build as the sibling that creates them. An agent can distinguish this tool from the build tool without opening either 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 per-action descriptions make clear what each action does and implicitly when to choose it, and the build sibling is explicitly named as the alternative for creating images. There is no explicit exclusion guidance against runtime_images_registries or sandbox-creation tools, so it falls short of a full when/when-not treatment.

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