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

Annotations already cover readOnlyHint, openWorldHint, and idempotentHint. The description adds that results are scoped to the account and includes a one-line description and starting price, but since an output schema exists, return details are redundant. It adds some context but not substantial behavioral depth beyond 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 sentences with the core purpose front-loaded and the alternative stated immediately after. No wasted words, and the structure is easy to parse.

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 the presence of annotations, an output schema, and full schema description coverage, the description provides everything necessary to understand the tool's purpose and routing. It does not need to explain return values or parameter details because those are covered elsewhere.

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% and the single parameter (media) has an enum and a description in the schema. The tool description does not mention the media parameter at all, so the schema alone carries the full burden, making a baseline 3 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 states a specific verb (List), resource (image and video models), and scope (available to this VerseIn account). It also distinguishes itself from the sibling get_model, which is for a model's settings, giving an agent enough to 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?

It explicitly directs the agent to use get_model for a model's settings, clearly establishing the alternative for a closely related operation. This leaves little ambiguity about when to use list_models versus its most similar sibling.

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