ar_list_repositoriesLists Artifact Registry repositories in a specified Google Cloud project and location, so you can inspect available container image repositories.
Lists Artifact Registry repositories in a project/location.
| Name | Required | Description | Default |
|---|---|---|---|
| location | Yes | Region, e.g. "us-central1", or "us" for a multi-region | |
| pageToken | No | ||
| projectId | No | GCP project id; defaults to GOOGLE_CLOUD_PROJECT env var |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. 'Lists' implies a read operation, but it does not state permissions needed, pagination behavior (though pageToken is a parameter), rate limits, or return characteristics. This leaves the agent with minimal safety and behavior context.
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?
A single, front-loaded sentence with no wasted words. It is efficient and easy to parse, though its extreme brevity borders on under-specification rather than ideal conciseness.
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?
With no annotations, no output schema, and an undocumented pageToken parameter, the description is too thin. It should at least mention pagination or confirm read-only/safe-listing behavior to be complete for an agent deciding how to call it 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?
Schema description coverage is 67%, with location and projectId described but pageToken undocumented. The description adds no parameter meaning beyond what the schema already states ('project/location' mirrors the existing location and projectId descriptions) and does not compensate for the missing pageToken explanation.
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 ('Lists Artifact Registry repositories') and adds scope ('in a project/location'), so an agent can distinguish it from write siblings like ar_create_repository. However, it does not explicitly differentiate from other list siblings such as ar_list_packages or ar_list_versions, leaving that inference to the name.
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?
No when-to-use guidance, no when-not-to-use conditions, and no alternatives named. The description only says what it does, not when an agent should choose it over sibling list tools or how it relates to the broader Artifact Registry workflow.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.