Advanced Reasoning

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

Annotations already provide readOnly, destructive, idempotent, and openWorld hints. The description adds behavioral context about the reasoning model (Sonar Reasoning Pro), step-by-step reasoning, and return format (numbered citations), which goes beyond annotations.

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 well-structured sentences: first sentence states purpose and model, second gives best uses, third mentions return format and filters, fourth gives alternatives. No wasted words, information is front-loaded.

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 complexity (5 params, 1 required, 100% schema coverage, output schema exists), the description sufficiently covers purpose, usage, and filtering options. Output schema handles return value details, so no further explanation needed.

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% with descriptions for all 5 parameters. The description adds context by summarizing filtering capabilities (recency, domain, context size) and their purpose, enhancing understanding 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 'Analyze a question using step-by-step reasoning with web grounding', specifying a specific verb and resource. It distinguishes from siblings by mentioning alternative tools for quick facts and comprehensive research.

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?

Explicitly states best use cases (math, logic, comparisons, complex arguments, chain-of-thought) and provides clear alternatives: 'For quick factual questions, use perplexity_ask instead. For comprehensive multi-source research, use perplexity_research instead.'

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