List images in a Depot project registry

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

Beyond the readOnlyHint/idempotentHint/destructiveHint annotations, the description explicitly states the operation cannot delete tags or images and explains WHY deletion is not exposed—it is irreversible and something may be deploying what you delete. It also discloses the DEPOT_PROJECT_ID fallback behavior, adding context the annotation booleans alone do not convey.

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 first sentence carries the core purpose, followed by short paragraphs for use cases, environment/parameter behavior, and a safety note. Every sentence earns its place, though four paragraphs is slightly more than strictly necessary for a simple list operation.

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 read-only list tool with an output schema, 100% schema parameter coverage, and four safety annotations, the description covers purpose, use cases, the projectId mechanism, and the read-only guarantee. Nothing an agent needs to invoke it correctly is missing.

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 100%, so all three parameters are already fully documented (limit bounds and default, pageToken semantics, projectId fallback). The description only restates the projectId fallback in prose without adding new parameter-level detail, so the baseline 3 applies.

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 a specific verb and resource: 'List the container images stored in a Depot project's registry, with tag, digest, push time, and size.' It names the exact returned fields, and no sibling tool covers image listing, so it is trivially distinguishable from the other fourteen depot_* tools.

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?

Three concrete use cases are given: verifying a build pushed what was expected, finding the digest behind a tag before deploy, and checking when an image was last refreshed. It also routes the agent to depot_list_projects when the projectId is unknown. No alternative tool is named for exclusion, but the provided scenarios make selection unambiguous.

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