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

Annotations already declare readOnly, idempotent, openWorld, non-destructive. The description adds the pay-per-prompt price ($0.04 USDC via x402), a data-purchase cap (0.02 USDC), KYA seller checks, and Claude-written briefs—substantial behavioral context 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?

One dense but front-loaded sentence: pricing model first, then orchestration and output. Parentheticals earn their place by clarifying budget and writer, though the sentence is longer than typical.

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 a paid, open-world orchestration tool with an output schema present, the description supplies the key invocation context: cost, payment protocol, data-buy cap, KYA, and brief output. Missing failure or budget-exhaustion behavior is a minor gap.

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 single prompt parameter is fully documented in the schema as 'Your question about Argus launches / Arc markets.' The description adds no further format, length, or constraint information, so with 100% schema coverage it stays at the baseline.

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 the tool answers a question by orchestrating sibling tools and external data, then writes a brief. The phrase 'the tools above' and 'other sellers in Fuci Market' differentiates it from single-source siblings, though the core verb 'answers' is broad.

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?

Implies use for questions where a synthesized, paid answer is desired and notes the agent will only buy data 'when it helps.' However, it never states when to use this agent instead of the individual Argus/Fuci tools, nor any exclusions.

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