List local models / explain a selector

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

Beyond the readOnlyHint and idempotentHint annotations, the description reveals behavioral details: explain_selector 'without spending a generation', the reporting of the 'full fallback chain', and the need to refresh after pulling a model. This adds real context about system behavior and costs that annotations alone do not convey.

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 three sentences, each serving a distinct purpose: the first states the core list function and output, the second covers filtering and refresh, and the third explains explain_selector with a usage recommendation. There is no redundant or filler content.

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?

The description covers the primary list function, filtering, refresh, and the advanced explain_selector feature, and also describes the output fields (capabilities, context window, size, loaded status). Since there is no output schema, this is sufficient. The tool's complexity is handled well because the schema documents all parameters and the description focuses on when and how to use them.

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%, so the baseline is 3. The main description adds operational meaning: it links `refresh` to post-pull actions, connects `resident_only` to avoiding load costs, and frames `explain_selector` as the recommended debugging entry point with the 'full fallback chain' detail. This is more than just restating the schema, though not dramatically so.

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 opens with a specific verb and resource: 'List the models installed on the Ollama host' and enumerates the output fields (capabilities, context window, size, loaded status). It also clearly introduces the second function, explain_selector, as a dry-run of the model resolver, which distinguishes it from siblings like ollama_dispatch and ollama_lifecycle.

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 provides clear conditional usage: 'pass `refresh` after pulling a new model', 'Filter with `capability` or `resident_only`', and for explain_selector, 'Start there whenever routing surprises you.' It gives context and a recommendation, but does not explicitly name alternative tools or state when not to use the tool.

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