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

Annotations already declare readOnlyHint=true, so the description does not need to restate that. It adds valuable behavioral context by noting that search_depth='advanced' incurs higher cost and that topic='news' or 'finance' narrows results, insights not present in the annotations. This goes beyond the structured data, though it does not mention potential rate limits or pagination, which could be useful.

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 three sentences, front-loaded with the primary purpose, followed by parameter guidance. Every sentence adds distinct value, with no filler or redundancy. It is appropriately concise while covering purpose, use cases, and parameter nuances.

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, full schema coverage, and read-only annotation, the description supplies all essential information: what it does, when to use it, and how to tailor parameters. The presence of an output schema means return value details are unnecessary, so the description is fully sufficient for agent selection and invocation.

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%, so the baseline is 3, but the description enriches parameter meaning by linking search_depth to complex research queries and cost, and topic to specific content domains (news, finance). These usage-oriented hints help the agent make better parameter choices than the bare schema descriptions alone.

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 identifies the tool as a real-time web search via Tavily, stating its purpose for current events, fact-checking, and research. This distinguishes it from the sibling tools, which are specific data lookups or calculations, leaving no ambiguity about what this tool does.

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 use cases (current events, fact-checking, research) and practical guidance on when to adjust parameters (search_depth for complex queries, topic for news/finance). However, it does not explicitly compare with alternatives like http_fetch or delegate_to_agent, so it lacks explicit exclusionary guidance, earning a 4 rather than a 5.

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