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

There are no annotations, so the description carries the full burden of disclosing behavior. It merely says 'search the web for information,' which minimally implies a read-only retrieval operation, but it does not disclose return format, result structure, rate limits, or any side effects. This is a significant gap for a tool with no annotation support.

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 short sentence, making it highly scannable and front-loaded with the action verb 'Use.' However, the phrase 'for information' is somewhat redundant; 'search the web' would suffice, so not every word earns its place.

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?

Given six parameters and no output schema, the description should clarify what the tool returns (e.g., search results with URLs and snippets) and any noteworthy behavior. It provides none of that, leaving the agent without enough context to fully understand the tool's response or capabilities beyond parameter names.

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 schema description coverage is 100%, so each parameter (query, engines, language, categories, time_range, max_results) is already documented. The tool description adds no semantic detail beyond the schema, but it doesn't need to since the schema is fully self-descriptive. Baseline 3 is appropriate.

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 action ('search the web') and the specific tool ('SearXNG'), giving the agent a solid understanding of what the tool does. Although it doesn't distinguish from siblings, no siblings are listed, so this is a clear purpose statement without being a tautology.

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 implies this tool is for web search, but it provides no explicit guidance on when to use it versus alternatives, nor any context about when it would be appropriate. With no sibling tools, the usage context is only implied rather than clearly stated.

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