Searxng Search App

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

With no annotations, the description carries the full burden and does well: it discloses the backing mechanism (web_search via the host-mediated MCP Apps bridge) and the capability boundaries of the launched app. It stops short of stating what launching twice does or how app/session lifetime behaves, which are the remaining behavioral unknowns for a UI-launching tool.

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?

Three sentences, front-loaded with what is launched, followed by the selection rule and then the scope exclusions. Every clause contributes and nothing is repeated from the schema.

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 one-optional-parameter tool with an output schema, the description covers purpose, mechanism, and boundaries adequately. It is slightly incomplete on app lifecycle semantics (what a second launch yields, whether state persists), which an agent may need to call it confidently in a multi-turn session.

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% and the single optional 'query' parameter is already documented in the schema as an initial query run on load. The description adds no further parameter semantics (e.g., how an empty query behaves in the UI), 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?

States a specific verb ('Launch') and a precisely scoped resource ('interactive SearXNG search-UI app'), then enumerates its components (query box, category filters, clickable results list). It explicitly distinguishes itself from web_search and from browser automation, so an agent can separate it from every sibling without opening a schema.

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?

Gives an explicit selection rule: use when a human should see and interact with results visually rather than read raw JSON, which maps directly onto choosing this over web_search. It also pre-empts the two most likely misuses by stating it does not drive a browser or render arbitrary web pages.

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