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

With no annotations, the description carries the full burden and does well: it discloses that each request is a stateless fresh conversation, that web search may or may not trigger, that the answer language follows the prompt, and that timezone anchors relative dates. It omits auth/permission needs and rate or cost limits, so it stops short of a 5.

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?

Front-loads what the tool does before listing return fields and usage, and every sentence carries information. It is one dense paragraph with a slightly redundant restatement of the language rule, so it is efficient but not perfectly tight.

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?

With no output schema and no annotations, the description compensates by fully describing the return payload (answer markdown, sources with domain/title/snippet/date/thumbnail, inline links, conversation title, model, web-search flag) and the key behavioral constraints. An agent has enough to call it correctly.

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 already documents both prompt and timezone fully. The description reinforces prompt-language and timezone semantics but adds no syntax or format detail beyond what the schema provides, so the baseline 3 applies.

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?

States a specific verb and resource ('Sends a prompt to ChatGPT and returns the answer as markdown text') and enumerates the return payload in detail. An agent can distinguish it from the sibling perplexity_chat answer tool by the explicit ChatGPT/web-search framing.

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 four concrete use cases (answer with cited sources, ground an agent/RAG pipeline, summarise current events, build answer datasets), giving clear context for selection. It does not, however, name an explicit alternative or state when NOT to use it (e.g., versus the Perplexity sibling).

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