list_engines

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

With no annotations provided, the description carries the burden of behavioral disclosure. It explains the parameter's effect (enabled_only filters to enabled engines by default), adding meaningful context beyond the schema. It does not mention return format or side effects, but for a simple list operation, the description is sufficiently 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 description is two sentences with a concise Args block, front-loaded with the core purpose. Every sentence earns its place, and the format is clean and easy to parse. No unnecessary information.

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 list tool with one optional parameter, the description covers the essential purpose and parameter behavior. It lacks explicit return format details, but the tool's name and purpose make the output largely predictable. Adequate for the tool's simplicity.

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 0%, making the description the sole source of parameter meaning. The description explains 'enabled_only: If True (default), return only enabled engines,' which provides clear semantics beyond the schema's type and default fields. This fully compensates for the lack of schema descriptions.

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 states the tool's function: 'List all available search engines from the SearXNG instance.' It uses a specific verb ('list') and identifies the resource ('search engines') and scope ('from the SearXNG instance'), which also distinguishes it from the sibling search tools.

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 context is clear: this tool is for listing engines, distinct from the search operations of its siblings. Although there is no explicit 'when to use' or alternative guidance, the purpose is self-evident and the tool's role is well-differentiated by the description.

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