pplx_query

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

Discloses cost: 'COSTS 1 PRO SEARCH QUERY per call.' Also notes which models support thinking mode. While it doesn't explicitly state read-only or idempotency, the description provides key behavioral context for a query tool, and annotations are absent, so the description carries the burden well.

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 efficient: a cost warning, usage guidance, and a parameter list with explanatory details. Every sentence serves a purpose, though the parameter list could be slightly more compact without losing clarity.

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 presence of many sibling tools, 4 parameters, and an output schema, the description covers all essential aspects: when to use, cost, model options, thinking constraints, source_focus flexibility. No gaps remain for the agent to make informed decisions.

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?

With 0% schema description coverage, the description fully compensates by explaining each parameter: query (the question), model (listing options), thinking (availability caveats), and source_focus (possible values). This adds substantial meaning beyond the schema's type/default definitions.

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?

Explicitly states 'Query Perplexity AI with explicit model selection', indicating a specific verb and resource. It distinguishes itself from siblings by emphasizing the need for explicit model choice, contrasting with pplx_smart_query's automatic routing.

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 clear guidance: 'Prefer pplx_smart_query for automatic quota-aware routing. Use this only when you need a specific model or thinking mode.' This explicitly states when to use and when not, naming an alternative.

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