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

With annotations already declaring readOnlyHint and idempotentHint, the description adds meaningful behavior: cost ($0.05/call over x402, prepaid header, free tier), no wallet/API key required, and verdict thresholds (loss >15% or no route -> STOP/HOLD, high concentration -> HOLD). The thresholds are slightly ambiguous in distinguishing STOP vs HOLD, but the description still adds transparency 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?

The description is moderately long (~120 words) and front-loaded with the verdict. However, it duplicates schema info ('size is in USD (default 100)', 'Required input: token') and is somewhat repetitive at the start ('One call before buying' and 'The call to make before buying'). It could be tightened without losing value.

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 the output schema exists and the annotations cover safety, the description sufficiently covers input requirements, cost, access (no wallet/API key), and decision logic. It provides enough for an agent to call the tool correctly, with no major gaps.

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%, but the description adds semantic meaning by explaining that size is used for a USDC round trip through NEAR Intents to measure loss, giving purpose to the parameter beyond the schema's generic 'trade size in USD' description.

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 explicitly states the tool's purpose: a pre-trade gate that returns GO/HOLD/STOP for NEAR (NEP-141) tokens. It enumerates concrete checks (control, exit liquidity via USDC round trip, supply concentration) and clearly distinguishes itself from the generic sibling pre_trade_gate by scoping to NEAR.

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 says 'The call to make before buying a NEP-141 token,' providing clear when-to-use context. It does not explicitly name alternatives or when not to use it, but the context is sufficient for the agent to select this over generic gate tools.

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