List Images

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

Annotations already declare read-only/idempotent behavior. The description adds value by disclosing what the response contains (image name, OS flavor/version, architecture), which goes beyond the safe operation hint. It doesn't discuss pagination or rate limits, but for a list tool with no output schema, this is sufficient.

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 core purpose and remains concise. The bullet list adds useful detail without bloat. Minor redundancy between 'available OS images' and 'system images (operating systems)' prevents a perfect score.

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 operation with two optional, fully described parameters and no output schema, the description adequately covers purpose, output content, and usage context. The only gap is not explicitly mentioning that the tool can also list snapshots/backups/apps via the 'type' parameter, but the schema handles that.

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% with both 'type' and 'response_format' fully documented. The description adds minimal new parameter meaning—only reinforcing that system images are the default focus. No additional syntax or format details beyond the 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 states a specific action ('List available OS images') and resource ('for creating servers'), clearly distinguishing it from sibling tools like list_servers or list_locations. It also notes the tool's purpose in server creation workflow.

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?

Provides clear usage context: 'Use this to find the right image when creating a new server.' While it doesn't mention when not to use it or name alternatives, the tool is unique among siblings for image listing, so exclusions are unnecessary.

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