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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds useful context like 'maximum 20 results per request' and mentions content filtering and region-specific searches, but does not cover aspects like rate limits, authentication needs, or error handling, leaving 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 appropriately sized with three sentences that efficiently cover purpose, usage, and constraints. It is front-loaded with the core function and avoids unnecessary repetition, though minor improvements in flow could elevate it to a 5.

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 moderate complexity (3 parameters, no output schema, no annotations), the description provides a basic overview but lacks details on return values, error cases, or advanced usage. It is adequate for a simple search tool but incomplete for robust agent interaction.

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 fully documents all parameters. The description does not add any parameter-specific details beyond what the schema provides, such as explaining the impact of 'safeSearch' levels or query formatting. Baseline 3 is appropriate as the schema handles 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 DuckDuckGo' with specific use cases like 'general queries, news, articles, and online content.' It distinguishes itself as a general-purpose search tool, though without sibling tools to differentiate from, it cannot achieve a perfect 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 implied usage guidance with phrases like 'ideal for general queries' and 'use this for broad information gathering,' but lacks explicit when-not-to-use scenarios or alternatives. Without sibling tools, it cannot offer comparative guidance, limiting its score.

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