Perplexity Web MCP

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pplx_ask

Ask a question and receive an AI-generated answer via Perplexity's auto-selected model; optionally set source focus or continue a conversation.

Instructions

Quick Q&A with auto model. COSTS 1 PRO SEARCH QUERY. Prefer pplx_smart_query(intent='quick') for simple lookups (Sonar 2 first).

An omitted source_focus falls back to your saved default (set with pwm config), then web.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`query`	Yes
`source_focus`	No
`conversation_id`	No

Output Schema

TableJSON Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed3 schema fields changedv0.16.0Sep 30, 2026
- addedInput schema / properties / source_focus / anyOf
```
Added value: +[
+  {
+    "type": "string"
+  },
+  {
+    "type": "null"
+  }
+]
```
- changedInput schema / properties / source_focus / default
```
Previous value: -"web"New value: +null
```
- removedInput schema / properties / source_focus / type
```
Removed value: -"string"
```
First observedv0.14.0Jul 4, 2026

TDQS

A4/5.0

Behavior4/5

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

With no annotations, the description carries the full burden, and it delivers two non-obvious behaviors: the per-call cost (1 Pro Search Query) and the source_focus resolution chain (saved default from `pwm config`, then web). It omits return shape and whether conversation_id threads state, but the cost and fallback precedence are exactly the kind of context annotations would otherwise supply.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The cost warning is front-loaded, the alternative is given next, and the source_focus default rule follows. Three short lines with no filler; every sentence carries decision-relevant information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be described. The description covers purpose, cost, the preferred alternative, and the source_focus fallback; the only meaningful gap is conversation_id semantics (whether the Q&A continues an existing thread).

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0% for 3 parameters, so the description must compensate. It does so for source_focus (a genuinely non-obvious default-resolution rule) while query is self-evident from the Q&A framing, but conversation_id is left entirely undefined in both schema and description.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Quick Q&A') plus the model-selection behavior ('auto model'), and it names the sibling pplx_smart_query as the preferred path for simple lookups. It is clearly distinguishable from the deep-research and single-model siblings, though it doesn't fully contrast against pplx_query/pplx_sonar.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly routes the agent: 'Prefer pplx_smart_query(intent='quick') for simple lookups (Sonar 2 first)', with a concrete cost signal ('COSTS 1 PRO SEARCH QUERY') to shape selection. It gives when-to-use and a named alternative, but no explicit when-not or prerequisite conditions.

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