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

Annotations already establish readOnly=true, destructive=false and openWorld=true, so the safety profile is covered; the description goes further by disclosing that the tool is paid, the two payment mechanisms (x402 USDC on Base or an API key costing 1 credit), and the external data sources queried. Cost-per-call is a genuinely important behavioral trait for an agent deciding whether to invoke, and it also explains the idempotentHint=false despite readOnly=true. It does not state rate limits, caching, or failure behavior for an unknown address, keeping it below a 5.

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?

Two sentences, zero filler, and the most decision-relevant fact for an agent ('Paid.') is front-loaded. The returned signals are listed compactly in the second sentence with no redundancy against the title or schema.

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, the description must convey what comes back, and it does so explicitly by naming the four result components including an 'explainable' risk score. The payment model is also covered, which matters because the call has a cost. It lacks detail on response shape and on what happens when an address has no records, which is the remaining gap for a paid single-address lookup.

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 description coverage is 100% and the single 'address' parameter is documented with a concrete base58 example, so the schema carries the parameter burden. The description only restates 'for one TRON address', adding no format, normalization, or validation meaning beyond the schema. Baseline 3 is appropriate when the schema is this complete.

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 names a specific resource (one TRON address) and enumerates exactly what is returned: USDT freeze status, OFAC SDN and OpenSanctions matches, Chainabuse reports, and an explainable risk score. That is far more specific than a generic 'screen an address'. It stops short of a 5 because it never names or contrasts the two siblings (check_tron_usdt_blacklist, tron_usdt_aml_report), leaving the agent to infer the boundary itself.

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?

There is no explicit when-to-use or when-not-to-use guidance. The description implies a screening call for a single address, but with two closely related siblings in scope it gives no rule for choosing between a full screen, a blacklist check, or an AML report. The only decision signal offered is the 'Paid.' prefix, which is a cost warning rather than a routing guideline.

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