SMX: market list from the agent API (paid)

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

Goes well beyond the annotations by disclosing the exact price ($0.01 in Circle testnet USDC on Base Sepolia via x402), which wallet key is charged, that the tool makes no call without X402_PRIVATE_KEY, and that 400/404 errors are not billed. This is precisely the operational context an agent needs before invoking a paid endpoint.

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?

Information is front-loaded (what it returns, then cost/mechanics) and every clause carries signal. Minor redundancy in restating 'SMX agent API market list' alongside the endpoint path and 'as served by the SMX agent API' costs it the top score.

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?

No output schema exists, so the description compensates by naming the returned fields, and it covers payment mechanics, credential requirements, and error-billing behavior. Nothing an agent needs to call this paid endpoint correctly is missing.

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 a single optional parameter at 100% schema description coverage, the schema already fully documents the `all` flag. The description's phrase 'the listed SMX testnet markets' loosely implies the default listed-only behavior, but adds no syntax or semantics beyond what the schema provides — the baseline of 3 applies.

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 combination ('market list' via GET /agent/markets) and enumerates the returned fields (status, outcome, midpoint with midBps/midPriceCents, minimum order). It explicitly distinguishes itself from the sibling smx_list_markets by naming it and noting it serves identical data.

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?

Names the free alternative (smx_list_markets) directly, which is the key routing decision for the agent. However it never states positively when the paid variant should be preferred over the free one, leaving the choice implicit rather than giving an explicit condition or exclusion.

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