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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the description's added value is the $0.05 cost, the live-vs-stale distinction against decision.sample, and the explicit scope exclusion (no trade plan, execution check, evidence or risks). It does not mention rate limits or what happens when a symbol is unknown, which keeps it short of 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, front-loaded with the price and the returned payload, then the sibling routing. Despite being dense, every clause carries selection-relevant information and none is filler.

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?

There is no output schema, so the description carries the return-value burden, and it discharges it by listing the fields produced and the ones deliberately omitted. Combined with the cost and freshness cues, an agent has everything needed to choose and call it correctly.

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 both parameters are already documented and the baseline is 3. The description adds meaning by tying the optional 'side' parameter to its outcome ('a GO/WAIT answer for a side'), clarifying why an agent would supply it rather than omitting it.

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 concrete verb+resource (a live trading decision) and enumerates the returned signals: action (STRONG_BUY..STRONG_SELL), direction, conviction, GO/WAIT, pillar stances, measured hit rate. It also names the full-server counterpart get_decision, so the agent can distinguish it from siblings without opening a schema.

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 instructs 'Use as the default decision' and then routes away from the two nearest siblings: decision.pre_trade is only go/no-go timing for a side, and decision.sample is free but an hour old. When-to-use, when-not, and alternatives are all present.

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