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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, covering safety and idempotency. The description adds a critical operational dependency ('Requires API key') and discloses the exact return structure (list of fields), which helps the agent anticipate output. No contradiction with 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?

The description is three sentences: purpose/scope, usage guidance, and return fields/API key requirement. Every sentence carries distinct, non-redundant information and is front-loaded with the core function. No wasted words.

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?

This tool has moderate complexity with multiple data sources and a variable output, but the description lists all return fields, and the schema fully documents the sole parameter. It omits potential limitations like rate limits or data freshness, but the agent has enough to invoke and interpret results.

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 schema has 100% coverage for the single parameter 'query', including examples, so the description need not reiterate semantics. The description adds no parameter-specific detail beyond the schema, but the baseline of 3 is appropriate given the high schema coverage.

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 performs deep blockchain forensics, enumerating specific data types (DEX pool health, TVL trends, token price behavior, whale flows) via DeFiLlama + DexScreener. This distinguishes it from siblings like x711_price_feed by emphasizing a comprehensive analytical scope. The phrase 'Use before any DeFi transaction' adds a concrete use case.

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?

Provides explicit when-to-use guidance: 'Use before any DeFi transaction to assess real-time protocol health.' This establishes a clear context for invocation. It does not explicitly name alternatives or exclusions, preventing a 5, but the guidance is unambiguous.

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