Get Last Image

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

Annotations already mark this as read-only, idempotent, and non-destructive. The description adds meaningful behavioral detail by specifying the scope ('most recently generated or edited') and enumerating the returned metadata fields, which is especially useful since there is no output schema.

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 states the action, resource, and return fields without any filler. Every part earns its place, and the most important qualifier ('most recently') appears early.

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 no-argument, read-only tool, the description adequately covers what the agent needs to know: what it returns and how the target is selected. It could mention edge-case behavior (e.g., when no image exists yet), but this is a minor gap given the low complexity and clear annotations.

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?

The tool has zero parameters, so the baseline is 4; the schema fully covers the parameter surface. The description's mention of 'most recently generated or edited' helps clarify what the implicit selection criterion is.

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 uses a specific verb ('Get metadata') and names the exact resource ('the most recently generated or edited image') with the fields returned (file path, MIME type, timestamp, size). This clearly distinguishes it from sibling tools like generate_image, edit_image, and list_models.

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 phrase 'most recently generated or edited image' gives clear contextual guidance: use this tool when you need metadata about the latest image from generation or editing workflows. It does not explicitly name alternatives or exclusion conditions, but the usage context is evident from the siblings.

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