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

Annotations already provide readOnlyHint=false and idempotentHint=true; the description adds useful payment behavior: it is paid, costs $0.25, uses USDC on Base or Arbitrum One, and requires x402. However, it does not disclose side effects, idempotency expectations, or what happens after payment, which matters because readOnlyHint is false. No contradiction with 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?

The description is short and mostly to the point, but it contains redundancy: 'MONETIZED VIA x402', 'paid tool, not free', and 'with an x402 payment' repeat the same idea. The main endpoint is placed at the end of the third sentence and the opening sentence is vague rather than a precise summary of the tool's function.

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 4 parameters, only one required, and a low schema-coverage rate, the description leaves too much to inference. It supplies payment routing but omits parameter semantics, usage conditions, and side-effect expectations. Since the output schema exists, return value documentation is not needed, but the other gaps are material enough that an agent could call the tool incorrectly.

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 coverage is only 25% and the description provides no parameter explanations. Required idempotency_key, gpu, limit, and agent_wallet are never described in the prose; only agent_wallet has a schema note. The description mentions payment amounts but does not help the agent understand how to populate any field.

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?

The description does not state a concrete verb or resource; 'Agents pay for work and prove what happened' is vague and could describe payment, proof, or history retrieval. The endpoint path is the clearest clue, but the description never says it lists or retrieves compute history. It also does not differentiate compute_history from siblings like compute_spot_prices or compute_alerts.

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?

The description gives payment and endpoint details but no guidance on when to use this tool versus compute_spot_prices, compute_alerts, or other siblings. There are no conditions, exclusions, or alternative-selection hints. The only usage signal is that the tool is payable, which is not enough to route an agent correctly.

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