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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing the x402 payment handshake (first call returns PaymentRequired, retry with _meta['x402/payment'], success returns _meta['x402/payment-response']) and a safety gate on null SL/TP. These are non-obvious runtime behaviors an agent could not infer from annotations, and nothing contradicts readOnlyHint since the tool only returns a decision rather than executing trades.

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?

Four sentences, front-loaded with the decision purpose, then return values, then the safety guardrail, then the payment mechanics. The dense comma-separated output list is slightly hard to parse, but every sentence carries actionable information and nothing is redundant.

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?

With no output schema and no parameters, the description carries the full burden and does so: it lists the returned fields, explains the null-SL/TP condition, and covers the two-call x402 payment sequence. An agent has everything needed to invoke it and interpret the result correctly.

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 schema has zero declared properties, so there is little to explain, and the description usefully documents the out-of-schema _meta['x402/payment'] key required on retry. That is genuine added meaning beyond an empty schema, though the exact shape of the payment payload is still left unspecified.

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 decision verb and resource: 'Decide whether to open, avoid or manage a XRP 4H trade', then enumerates the exact outputs (LONG, SHORT, NEUTRAL/NO TRADE, Entry, SL, TP, strength, diagnostics). The asset-specific naming clearly separates it from siblings like get_btc_4h_setup and get_eth_4h_setup without needing to open any 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 concrete when-to-use framing ('open, avoid or manage') plus an explicit negative rule: 'If SL or TP is null, do not open a new position.' It does not, however, mention when to prefer the sibling prepare_xrp_4h_purchase, so the routing between this tool and the payment-preparation family is left implicit.

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