list_modelsList Zerouter model IDs and the endpoint each uses, with optional substring filtering, so you can pick the right model for chat or API calls.
List model IDs available on Zerouter and the endpoint each one uses. Uses GET /v1/models when ZEROUTER_API_KEY is set, otherwise the public catalog at https://www.zerouter.ai/models.
| Name | Required | Description | Default |
|---|---|---|---|
| filter | No | Optional substring filter, e.g. 'gemini' |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint and openWorldHint; the description adds meaningful context beyond that — the backend endpoint used (GET /v1/models) and the fallback to a public catalog when the API key is absent, which is genuinely useful behavior disclosure.
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: what it returns is front-loaded, followed by the auth-dependent sourcing rule. No waste.
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?
Complete for a simple read-only list with one optional param and no output schema; the auth/fallback behavior is the key context an agent needs. Missing only explicit sibling routing guidance.
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 'filter' param is fully documented as an optional substring filter, so the description doesn't need to elaborate. Baseline 3 applies since schema carries the parameter burden.
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?
States a specific verb (List) and resource (model IDs available on Zerouter) plus what it returns alongside each ID (the endpoint each one uses). Clearly distinguishable from siblings like get_pricing and compare_models.
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 by the name and the auth-dependent behavior described (ZEROUTER_API_KEY set vs public catalog), but it never explicitly says when to choose this over compare_models or get_pricing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.