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

Annotations already declare readOnly/idempotent/closed-world, yet the description adds substantial non-obvious behavior: it is free, runs exactly one completed UTC close behind, updates every calendar day including weekends, and stamps output with signal_close_date. This staleness and cadence disclosure is exactly the kind of trait an agent cannot infer from 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 resource and its outputs before the risk-on/risk-off framing and operational caveats. Dense but every clause carries substantive meaning; the parenthetical enumerations are informative rather than 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?

With no output schema, the description carries the full burden of explaining returns and does so completely: it names each signal, the gate hierarchy, the overriding master gate, and the timestamp field. An agent has enough to interpret the response without additional documentation.

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?

The tool takes zero parameters, so the baseline is 4 and there is no parameter syntax to clarify. The description instead spends its words defining the returned fields (LONG/CASH states, gates, price and day change), which is beyond any schema burden here.

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 resource (BTC/ETH trend signal) and enumerates the exact outputs: long-only state per sleeve, 50-day trend gate, and the BTC 200-day master gate. It explicitly frames itself as a rules-based verdict rather than raw price data. It does not explicitly differentiate from the sibling get_crypto_trend_live, though 'exactly one completed UTC close behind' implicitly contrasts the lagged vs live variants.

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 positions the tool as 'a rules-based risk-on/risk-off verdict, not raw price data,' which implies the correct use case versus price-data siblings. However, it never names get_crypto_trend_live or states when to prefer the lagged version over the live one, leaving the alternative selection to inference.

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