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

With no annotations, the description bears full responsibility for disclosing behavior. It mentions the payment requirement (via x402 or subscriber key) and includes an educational disclaimer ('not financial advice'), but does not explicitly state whether the tool is read-only, rate-limited, or has other side effects.

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 somewhat verbose, repeating payment instructions and usage hints. It could be more concise (e.g., removing redundant phrases like 'Cheapest first call' and 'Browse every tool + price first'). However, it is structured in clear sentences and not excessively long.

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?

The description covers the tool's purpose, cost, payment method, data source (40-source bot), and output components (regime, confidence, VIX, ADX). It lacks explicit output format details (e.g., JSON structure) but provides sufficient context for a zero-parameter tool. The suggestion to use get_catalog for browsing adds useful context.

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 schema coverage is 100%. The description adds no parameter-specific information, but there are none to explain. This aligns with the baseline of 3 for high schema coverage with no parameter details.

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 the tool provides live crypto & equity market regime classification with specific categories (TRENDING, MEAN_REVERTING, VOL_EXPANSION) and includes confidence, VIX, and ADX context. It distinguishes itself from other get_* sibling tools by focusing on market regime.

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 mentions 'Cheapest first call on this API' and suggests using the FREE get_catalog tool to browse all tools and prices, providing some guidance on when to use this tool relative to alternatives. However, it does not explicitly state when to use this tool over others (e.g., for a market-regime overview).

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