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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered; the description adds behavior beyond that — the composite three-signal methodology, the categorical output with reasons, the price and tier behavior (0.25 base, 0.175 above ten payments, 5-call pack), and the alternate payment paths via payment_tx or bundle_token. It does not disclose latency, data freshness, or failure modes for missing signals, which keeps it from 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?

The methodology sentence is front-loaded and dense but readable, and the pricing clause earns its place as decision-relevant cost information. The trailing 'After: POST /signal ... (the result's next field has the exact call)' is terse to the point of being cryptic and slightly interrupts the flow, costing a point.

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 usefully compensates by naming the three possible outputs, the reasons payload, and the 'next' field that feeds the downstream call. For a read-only gate with fully documented parameters, that is close to sufficient; missing are the ordering or weighting of the signals and what happens when a signal source is unavailable.

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% and all four parameters carry their own descriptions, including the pattern constraints and the tier-quoting behavior of payer_address, so the schema does the heavy lifting. The description adds only that the symbol denotes a coin and that payment alternatives exist, which is largely restatement; the baseline 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?

The description names a concrete verb and resource — a risk gate on a coin producing risk_on/neutral/risk_off — plus the three underlying signals (Fear and Greed and its change, predicted perpetual funding across venues, 4h EMA trend on Binance spot) and the reasons field. That is far more specific than the title alone. It stops short of a 5 because it never contrasts itself with nearby siblings such as historical_gate or token_risk, so the agent must infer the boundary from names.

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?

It states the use condition precisely ('Risk gate before opening a position on a coin') and the follow-on step ('After: POST /signal with the bias the gate allows'), which places it correctly in a workflow. It offers no explicit exclusions or 'use X instead when' guidance, so the agent is not told when to skip the gate (for example, historical analysis or non-crypto targets).

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