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

No annotations are provided, so the description must fully disclose behavioral traits. It mentions that the search is 'in real time' and returns 'comprehensive content from the most relevant sources,' which adds some context. However, it lacks details on critical aspects like rate limits, authentication needs, error handling, or the format of returned content (e.g., links, summaries). For a tool with no annotations, this leaves significant gaps in behavioral understanding.

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 concise and well-structured, consisting of two sentences that efficiently convey the tool's purpose and usage guidelines without unnecessary details. Every sentence adds value: the first defines the action and context, and the second specifies when to use it and what it returns. There is no wasted verbiage, making it front-loaded and easy to parse.

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 the tool's complexity (a web search with two parameters) and the absence of annotations and output schema, the description provides a basic but incomplete picture. It covers the purpose and usage context adequately but lacks details on behavioral aspects like performance, limitations, or output format. For a tool with no structured output information, the description should ideally hint at return types or content structure to be more complete.

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 input schema has 100% description coverage, with clear documentation for both parameters (query and depth), including examples and enum values. The description does not add any parameter-specific information beyond what the schema provides, such as explaining how 'depth' affects search results in more detail. Given the high schema coverage, the baseline score of 3 is appropriate, as the description does not compensate with additional semantic value.

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 purpose: 'Search the web in real time using Linkup' specifies the verb (search) and resource (web via Linkup). It further elaborates on the type of information retrieved ('trusted facts, news, or source-backed information'), making the purpose clear. However, since there are no sibling tools mentioned, it cannot differentiate from alternatives, preventing a score of 5.

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 explicit guidance on when to use this tool: 'whenever the user needs trusted facts, news, or source-backed information.' This gives clear context for its application. However, it does not specify when not to use it or mention any alternatives, as there are no sibling tools, so it falls short of a perfect score.

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