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

No annotations are provided, so the description carries the behavioral burden. It discloses the pricing unit and currency, which is useful, but it does not describe output shape, ordering, whether provider filtering changes behavior meaningfully, or any limits. This is acceptable for a simple list tool but not richly transparent.

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 English portion is two short, purposeful sentences with the core action and usage guidance front-loaded. The Russian translation duplicates the English content, which is somewhat redundant, but the overall length is still modest and readable.

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 low-complexity tool with one optional parameter and no output schema, the description covers the main decision points: what is listed, in what unit, and when to use it. It could mention what the returned list contains or how the provider filter behaves, but nothing critical is missing for basic invocation.

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% and the single optional provider parameter is already described in the schema. The description adds no new parameter-level semantics, so the baseline of 3 applies.

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 action ('list') on a specific resource ('available Store API models') and adds the defining detail: prices in rubles per 1M tokens. This clearly distinguishes it from siblings like ask_model, balance, and generate_image.

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 explicitly instructs to use the tool before ask_model to pick a model, giving clear contextual usage. It does not mention when not to use it or compare against other siblings, but for a simple listing tool the guidance is sufficient.

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