Deep Research

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

Annotations already declare readOnlyHint, openWorldHint, and non-destructive behavior. The description adds valuable behavioral context beyond annotations: 'Significantly slower than other tools (can take minutes)' and 'Returns a detailed response with numbered citations,' which are not evident from the annotations alone.

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: it starts with the core function, then best-for use cases, output characteristics, performance caveat, and alternatives. Every sentence serves a purpose without redundancy or fluff.

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 and the existence of an output schema, the description covers purpose, usage guidance, performance, output format (citations), and alternatives. It is fully self-contained and insufficient in no aspect, so it earns a 5.

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 schema covers 100% of the parameter (messages) with role/content definitions, so baseline is 3. The description does not add specific parameter-level details but contextualizes the input as a 'topic,' which is already implied by the schema. No significant added meaning beyond the schema.

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 function: 'Conduct deep, multi-source research on a topic' with a specific verb and resource. It explicitly distinguishes from siblings by mentioning 'high preset' and contrasting with perplexity_ask and perplexity_reason, making the purpose unambiguous.

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?

Provides explicit guidance on when to use this tool ('Best for: literature reviews, comprehensive overviews, investigative queries needing many sources') and when not to: 'For quick factual questions, use perplexity_ask instead. For logical analysis and reasoning, use perplexity_reason instead.' This clear alternatives/exclusion structure earns a top score.

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