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

With readOnlyHint=true and openWorldHint=true already covering the safety profile, the description still adds substantial behavior: it drops stubs, ranks by a stated formula (unique payers × 3 + calls + recency), enforces the budget as a hard filter, tiebreaks on price, and clarifies 'Advise-only — no payment happens here'. That is context well beyond the 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?

Front-loaded with the key fact (legacy alias, prefer verified_route), and the dense sentences each carry information. Slightly repetitive — verified_route is referenced twice — and 'price- tiebreaks' has a garbled spacing, but overall it is tight for the amount of behavior it conveys.

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?

For a read-only, open-world routing tool with no output schema, the description covers what it returns (ranked candidates + recommendation + ready-to-pay details) and what it does not do (no payment). Nothing an agent needs to call it 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?

Schema coverage is 100%, so the baseline is 3. The description adds meaning beyond the schema by framing budget as an enforced exclusion ('Tools priced above this are excluded') and tying need to the vetting flow, which gives the agent operational context the schema does not.

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 (find and judge the best paid x402 tool for a need) and immediately distinguishes itself from its sibling by declaring it is the 'legacy alias of verified_route'. It also names the discovery sources and ranking basis, so the agent knows exactly what the tool does without opening anything else.

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?

Explicitly says to prefer verified_route, explains the condition that selects it ('same vetting, matches the paid tool + Bazaar listing'), and gives concrete trigger phrases ('which x402 tool for X', 'find a paid API for X under $Y'). When-to-use and the alternative are both spelled out.

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