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

The annotations already declare this as read-only, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds useful behavior beyond annotations by saying the results are the user's named references and by enumerating the return fields, though it does not mention ordering or pagination.

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 three compact sentences with no wasted text and is front-loaded with the tool's purpose. The final sentence earns its place because there is no output schema and it tells the agent what fields each listed reference contains.

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 simple one-parameter read-only list tool, the description covers what is listed, how references are reused, and what fields are returned. The only parameter is fully documented in the schema, and annotations already cover the safety profile, so no critical context 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 coverage is 100% for the single optional includeHidden parameter, so the schema already carries the parameter meaning. The description does not mention includeHidden or its default, so it does not add parameter semantics beyond the schema; 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?

The description gives a specific verb and resource: listing the user's named references, explicitly defined as characters, objects, and other images saved under a name. This distinguishes the tool from generic file listings and from reference mutations such as create_reference, update_reference, and delete_reference.

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?

It explains how listed references are used later, via @Name in a generation prompt, which gives implied context for why an agent would call it. However, it does not explicitly say when to use list_references rather than list_library_files, create_reference, or other sibling tools, and it names no exclusions.

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