List Card Builder media files

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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds the underlying WS handler name and the path scoping ('www/card_builder/<path>'), which is genuine extra context, though the return-shape sentence partly overlaps the existing 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?

Four short lines, each with a distinct job (purpose, mechanism, usage, return), and the primary purpose is front-loaded. No filler.

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 rich annotations, an output schema, and a single well-documented parameter, the description is essentially complete for a read-only list operation. Only marginal value would be added by describing pagination or entry fields, which the output schema already handles.

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?

Only one optional parameter with 100% schema coverage, which already documents that empty string lists the root. The description reinforces the path prefix but adds no format or behavior the schema lacks; baseline 3 is appropriate.

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 (List) and resource (files and folders in the Card Builder media directory) plus the exact backing call card_builder/media/list and its path scope. An agent can distinguish this from card_builder_upload_media and card_builder_delete_media without opening a 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?

Explicit 'Use when' clause names the concrete condition (checking what's already uploaded) and the two sibling tools it precedes. This is a routing instruction, not an inference.

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