SearXNG MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It mentions the tool is 'ideal for general queries' and 'broad information gathering' which gives some context about scope, but doesn't address important behavioral aspects like rate limits, authentication requirements, result format, pagination behavior, or error handling. For a search tool with no annotation coverage, this leaves significant gaps.

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 appropriately sized with two sentences that each serve a clear purpose. The first sentence establishes the core functionality, while the second provides usage guidance. There's no wasted text, though it could be slightly more front-loaded with the most critical 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 search tool with 5 parameters, 100% schema coverage, but no annotations and no output schema, the description provides adequate basic context about when to use the tool. However, it doesn't compensate for the lack of output schema by describing result format or structure, and with no annotations, it should provide more behavioral context about the search operation's characteristics and limitations.

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%, so the schema already documents all 5 parameters thoroughly. The description doesn't add any parameter-specific information beyond what's in the schema. It mentions 'general queries' which aligns with the 'query' parameter, but provides no additional semantic context about parameter usage or interactions. Baseline 3 is appropriate when schema does the heavy lifting.

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 performs a web search using SearXNG API, specifying the action ('performs a web search') and resource ('SearXNG API'). It distinguishes from the sibling tool 'web_url_read' by focusing on search rather than reading specific URLs. However, it doesn't explicitly contrast with the sibling beyond implicit differentiation.

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 context for when to use this tool ('ideal for general queries, news, articles, and online content' and 'for broad information gathering, recent events, or when you need diverse web sources'). It gives positive guidance but doesn't explicitly state when NOT to use it or mention the sibling tool as an alternative for specific cases.

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