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

Annotations already declare readOnly, idempotent, non-openWorld, so the safety profile is covered. The description adds real context beyond that: 24/7 availability, that it is a trimmed slice of a fuller state map, what fields exist per coin (trend distance, tape lights, ATR%, RS vs BTC, room, volume z-score, UP/CHOP/DOWN), and freshness claims vs a delayed copy.

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 core content (top-3 of 81, BTC anchor, gate regime, breadth) in the first sentence, then the state-map contents. Slightly dense, and the paired negatives ('not a delayed copy', 'not a ranking or advice') lean toward redundancy, but nothing 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?

With no parameters, no output schema and safety covered by annotations, the description carries the remaining burden and does so well by enumerating the returned fields and scope. The one gap is the absence of an explicit freshness/refresh contract and how it differs from the _live variant.

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?

Zero parameters, so there is no parameter semantics to document and the baseline is 4. The description correctly implies a no-argument call by describing a fixed, always-on board rather than a queryable one.

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?

Specific verb+resource: a 24/7 crypto day-state snapshot limited to the top-3 of 81 Robinhood-tradable coins plus BTC anchor, BTC/ETH gate regime and breadth counts. It clearly says what the tool returns and even what it is not ('a state map, not a ranking or advice'), but it never names the sibling get_crypto_day_live, leaving the preview-vs-live distinction implicit.

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 'PREVIEW' framing and 'a live trimmed slice ... not a delayed copy' imply it's a lightweight snapshot, and 'Free' hints at a cost tradeoff versus heavier siblings. However it never states when to pick this over get_crypto_day_live, get_crypto_night or get_full_board, so routing is left to inference.

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