Download a free Fab asset file

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

Annotations indicate idempotentHint=true, openWorldHint=true, and destructiveHint=false. The description adds valuable context that the tool downloads to a local directory and never performs purchases or library operations, which aligns with annotations. It does not detail file overwrite behavior or other side effects, but the idempotency hint mitigates some concerns.

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 two concise sentences that convey the core purpose and a key behavioral distinction with no redundant information. It is front-loaded and efficient.

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?

Given moderate complexity (3 required params, output schema exists), the description covers the overall function and important behavioral notes but lacks parameter details. For a download tool, it is adequate but not fully complete without addressing parameter semantics.

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 only 33% (only acceptFabEula has a description). The description does not elaborate on 'listingIdOrUrl' or 'format', leaving agents to infer meaning from names alone. For low coverage, the description should compensate but does not.

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 clearly states the action (download), resource (free Fab file), and location (configured local download directory). It explicitly distinguishes itself from purchasing or adding to a library, which sets it apart from sibling tools like fab_search_assets or fab_get_asset.

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 description provides clear context for when to use the tool (downloading a free Fab file) and when not to use it (if the intent is to purchase or add to library). However, it does not explicitly mention alternative tools or prerequisites such as requiring a valid listing ID.

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