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

With no annotations provided, the description carries the full burden and does so well: it reveals this is a preview/trimmed slice, live (not delayed), and what data points are included (trend distances, tape lights, ATR%, etc.). It manages expectations by stating it is 'a state map, not a ranking or advice.' It does not mention auth, rate limits, or errors, but for a zero-parameter tool, this is strong transparency.

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 a tight three sentences. The first sentence defines what it is, the second elaborates on the state map contents, and the third clarifies what it is not and points to the full version. Every sentence adds value. It uses technical terms (ATR%, volume z-score) that are dense but relevant. Slightly heavy on jargon but not verbose.

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 no output schema or annotations, the description effectively conveys what data to expect: top-3 coins, BTC anchor, gate regime, breadth counts, and a list of per-coin fields. It also points to the full board for completeness. It does not detail the output format (e.g., JSON structure), but for a no-parameter tool, it covers the essential 'what' and 'why use this vs. alternative' well.

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 has zero parameters, so the baseline is 4. The description does not need to explain parameter semantics, and it doesn't, but it does explain the output structure, which is helpful. It correctly adheres to the rule that with no params, a score of 4 is appropriate.

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 clearly states a specific verb+resource+scope: 'crypto day-state PREVIEW' of 'the top-3 of 81 Robinhood-tradable coins by trend rank' plus additional indicators. It distinguishes itself from siblings by explicitly differentiating from the 'full 81-row board' available via get_crypto_day_live, and clarifies what it is not ('not a delayed copy', 'not a ranking or advice').

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 explicitly names the alternative for the full board: 'Full 81-row board: get_crypto_day_live (x402, pay-per-call).' This gives clear context on when to choose this preview vs. the pay-per-call full version. However, it does not discuss other siblings like get_crypto_night or when to use them, so it is not exhaustive but adequate.

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