openrouter_models

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

With no annotations, the description carries the full burden. It usefully discloses that results include capabilities and context lengths and that pricing data is stale (redirect to openrouter.ai/models), which is real behavioral context. It does not state how many models are returned, ordering, or whether listing is read-only/requires no auth.

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 first two sentences are front-loaded and tight. The trailing 'Tip: call earning_opportunities...' is unrelated promotional cross-sell that does not help an agent invoke this tool and dilutes focus.

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 simple, argument-light read tool with no output schema, the description covers purpose and returned fields adequately. It omits scale/format of the response and the sibling relationship, which would be needed for an agent to decide between this and openrouter_integration_guide.

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 parameter is a self-describing enum with a default, so the schema does the work. The description adds nothing about what the categories mean (e.g. what qualifies as 'fast' vs 'quality'), so the baseline 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?

Names a specific verb and resource ('Get list of popular OpenRouter models') and states the payload content (capabilities and context lengths), so an agent knows exactly what comes back. It does not distinguish itself from the related sibling openrouter_integration_guide, leaving that separation implicit.

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?

'Use this to choose the right model for your use case' gives one intended context, and the pricing pointer implies when NOT to rely on this tool. However, it never names openrouter_integration_guide as the companion tool nor states any exclusion or prerequisite, so routing is only implied.

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