list_cloud_run_services

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful context about the 'default environment' behavior, but it does not disclose pagination, return format, or permission requirements, leaving some behavioral gaps.

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 compact and front-loaded with the core purpose. The parameter explanations are brief, directly useful, and do not repeat schema information unnecessarily beyond what is needed for clarity.

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 simple read-only list tool with no required parameters, the description is nearly complete. It explains both parameters and the default environment behavior, which is enough for an agent to select and invoke the tool. A return-value or permission note would make it fully complete, but the absence is not critical at this complexity level.

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 0%, so the description carries the burden of explaining parameters. It does this well: 'limit' is defined as the maximum number of services to return, and 'environment' is explained with examples and default behavior. It could add a pointer to list_environments for valid environment values, but it is already effective.

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 clear verb and resource: 'List Cloud Run services.' It is specific enough to distinguish from sibling tools that list other GCP resources like compute instances or GKE clusters, though it does not explicitly differentiate itself from those siblings.

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 no guidance on when to use this tool versus alternatives. It explains how to use the environment parameter but does not mention when an agent should prefer this over list_compute_instances, list_gke_clusters, or list_environments.

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