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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavior: results are filtered to models that have a price, and the default model of each kind is included in the response. What it omits is whether unpriced/default models are flagged as such or how the entries are ordered.

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 tight sentences with no filler, and the resource identity is front-loaded before the inclusion constraint. The first sentence is a sentence fragment rather than a clause, which makes it slightly less self-explanatory than it could be, but nothing is wasted.

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 no output schema, the description must convey the return shape, and 'with the default of each' only gestures at the entry structure (model identity, default marker) without stating it. For a one-parameter read-only catalog tool this is adequate but leaves the agent guessing what fields each model entry actually contains.

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 0% for the single `kind` parameter, so the description carries the burden. It partially compensates by enumerating the three model categories (picture, edit, video), which map onto the enum values. It never says `kind` filters the listing or that omitting it returns all kinds, so the parameter's effect remains implicit.

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 names the resource concretely: 'The picture, edit and video models Tesseract can run, with the default of each.' The name supplies the verb (list), and the content makes clear this is a static catalog rather than a generation tool, which distinguishes it from siblings like generate_image or edit_image without naming them. It stops short of a 5 because it never explicitly frames the tool as a listing action or names an alternative.

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?

There is no when-to-use guidance, no mention of calling this before generate_image/edit_image/generate_video to pick a valid model, and no alternatives or exclusions offered. 'Only models with a price are offered' is a scope constraint on the results, not usage guidance. The agent must infer the call-before-generating pattern entirely.

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