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

With no annotations, the description carries the full burden and does so well: it discloses a refusal condition ('Refuses, with no charge, when live prices from ≥2 venues cannot be fetched'), a pricing model (x402 $0.10 USDC per call), a settlement-proof artifact, and an upstream dependency. It stops short of describing return structure, latency, or auth requirements, keeping it at 4.

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?

Purpose is front-loaded in the first clause, with supporting facts (dependency, proof, pairing, refusal, price) following in descending importance. Slightly dense with implementation details like the kind number and file path, but no sentence is wasted.

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 no output schema and no annotations, the description supplies the safety/cost/refusal profile an agent needs before invoking it. It lacks detail on what the returned entry/exit spread looks like, but the essential behavioral contract is present.

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?

There is a single 'task' parameter with 100% schema description coverage, so the schema already documents it and the baseline is 3. The description adds no format, example, or content expectations for the task string, so it does not exceed 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 a specific verb+resource ('Detects live cross-venue arbitrage spreads for a given asset') and explicitly clarifies the deliverable is an 'actionable entry/exit spread, not just a price delta'. It also distances itself from its nearest sibling by noting it is built on oracle.cross-chain-prices, so an agent can distinguish the two without reading either schema.

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?

Gives clear context for use by naming companion tools (crypto.investment-plays for a 'full execution plan') and the dependency on oracle.cross-chain-prices. It does not, however, state an explicit when-not or directly compare itself against alternatives like oracle.price-feed or oracle.volatility-monitor, so guidance is strong but not exhaustive.

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