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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds meaningful behavior: route availability is dynamic, and prices are only shown with an API key, including the USD/USDF pricing format. This is useful context beyond the structured 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?

The description is a single dense sentence that front-loads the main resource and lists the key output fields efficiently. It is slightly packed, especially the parenthetical pricing note, but no sentence 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 zero parameters, no output schema, and only basic annotations, the description carries the necessary burden of explaining what is returned. It covers the model fields, dynamic route availability, and conditional pricing, so an agent has enough context to call it correctly.

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?

The tool has zero parameters, so there is no parameter semantics burden. The description correctly does not invent parameter details, and the 0-param baseline 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 clearly identifies the resource (models served by the gateway) and the information returned (context window, output limits, route availability, conditional pricing). It does not explicitly differentiate this from the sibling list_tools tool, which is the main missing clarity point.

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?

Usage is implied: use this to discover available models and their pricing/limits. However, there is no explicit guidance on when to choose this over siblings like list_tools, nor any stated preconditions beyond the API-key note for pricing.

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