List the Fab assets this account owns

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description reinforces the read-only nature and adds the specific 'never claims or purchases' context beyond the generic hints. It also explains the unrealOnly filter behavior (filtering to what fab_import_asset can convert), which is useful behavioral context beyond the schema. No contradictions with annotations.

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?

Two concise sentences, with the core action front-loaded and the usage guidance in the second sentence. No redundant or filler content; every clause earns its place.

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 tool with two optional parameters, a rich output schema, and strong annotations, the description covers purpose, usage guidance, the read-only caveat, and the filter semantics. Nothing an agent needs to invoke it correctly is missing.

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%, so the schema already documents both parameters thoroughly. The description adds a high-level explanation of the unrealOnly filter ('ones that publish an Unreal artifact fab_import_asset can convert') and mentions 'optionally filtered' for query, but this largely paraphrases the schema. It adds minimal incremental value, so a 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 exactly what it does: 'List every listing already in the signed-in Fab library,' with a specific verb and resource. It also distinguishes itself from siblings by mentioning the optional unrealOnly filter and explicitly pointing to fab_search_assets as the alternative for free assets, so an agent can tell them apart.

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?

Explicitly instructs when to use it: 'Search free assets first with fab_search_assets; reach for this when you want something already paid for.' Also clarifies what it does not do ('it never claims or purchases'), giving clear exclusions against other tools like fab_download_free_asset or purchasing actions.

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