list_firmware_images

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

No annotations, so the description carries the burden, and it does well: it discloses the non-obvious filter fallback (returns every stored image when the code is omitted OR when there is no match) and names the error key. It does not state read-only characteristics explicitly or any permission requirements, which is the remaining gap for a zero-annotation tool.

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?

Front-loaded with the purpose and the sibling comparison, then the arg and return details. The Returns section partly restates what the output schema already declares, which is mild redundancy, though the section's structure (status/image_list/message) stays tight.

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?

Covers purpose, the one parameter's semantics including its fallback, and the shape of the result, so an agent can call it correctly. What remains unstated — read-only/auth assumptions and whether results span ADOMs — is minor for a simple list operation with an output schema present.

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 must compensate, and it does: the single `system` param is documented as a product code with concrete examples ("FMG", "FGT"), marked optional, and given its no-match fallback behavior, which is far beyond the bare `string|null` schema. Only format/case-sensitivity details are missing.

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 ("List firmware image files stored on the FortiManager's local disk") and immediately positions it against a named sibling by describing itself as "a subset of what list_available_firmware reports." An agent can distinguish local-cached images from FortiGuard-available images without opening either schema.

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?

Explains the selection context clearly — this tool covers files already imported/downloaded and pushable without fetching, implying list_available_firmware is for the broader catalog. It lacks an explicit "use X instead when..." directive, but the comparative framing gives an agent enough to choose correctly.

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