registry_image_config

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

Annotations already mark the tool as read-only and non-destructive. The description adds valuable behavioral context: multi-hop resolution (manifest -> platform entry -> config blob), stripping of `:tag`/`@digest` from repository, default platform behavior, and credential override behavior. It also discloses the return format. This goes beyond the annotation's simple safety profile, though it does not cover failure modes or rate limits.

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 well-structured and front-loaded. The opening sentence states the core function, followed by a useful list of extracted fields, then a brief explanation of resolution hops. The `args` list is clear and the `returns` note completes the picture. Every sentence serves a purpose without redundancy.

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 registry inspection tool with no output schema, the description provides complete context: purpose, parameter semantics, multi-platform resolution, credential handling, and the exact return dictionary. It is self-contained and leaves the agent with sufficient information to select and 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?

Although the input schema has zero descriptions (0% coverage), the description's `args` section thoroughly documents all five parameters: repository, reference, platform, username, and password. It explains defaults, overrides, and special behaviors such as '`:tag`/`@digest` is stripped — pass via `reference`'. This fully compensates for the sparse schema.

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: 'Fetch and parse an image's config blob from a registry without pulling.' It then enumerates the exact contents (env vars, entrypoint, cmd, workdir, ports, user, labels, layer history) and explicitly contrasts with sibling `registry_manifest`, which only points at the config digest. This makes the tool's purpose unmistakable and distinguishes it from related 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?

The description implies use when you need to inspect an image's configuration without pulling it, and explicitly contrasts with `registry_manifest`. It also provides context about multi-platform resolution and auth overrides. However, it does not explicitly state when not to use this tool or name alternative tools like `image_inspect` or `image_registry_data`, leaving some room for ambiguity.

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