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

With no annotations provided, the description carries the transparency burden. It discloses the free vs. premium tier difference, the authentication methods (session_token from verify_wallet_ownership or x402 payment proof), and that the data is public. It does not mention rate limits or exact failure modes, but it adequately sets expectations for a read-only data query.

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 front-loaded with the primary purpose and covers necessary details. The middle sentence is somewhat long and packs multiple ideas, but every sentence contributes meaningful information without excessive verbosity.

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 output content, free/premium behavior, authentication, and public data status. With no output schema, this is sufficient context for an agent to select and invoke the tool. Minor gaps exist, such as not detailing the exact response format or pagination, but these are not critical for this use case.

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 provides only parameter names and defaults with no descriptions (0% coverage). The description compensates fully by explaining ticker as an optional filter, and both session_token and payment as premium access mechanisms, even specifying where session_token comes from. This is excellent value beyond the schema.

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 identifies the tool's function: retrieving recent large on-chain whale moves, including tokens, USD size, and direction. It distinguishes itself from sibling market data tools by focusing specifically on the whale feed and provides concrete details about the data returned.

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 conveys a clear use case (monitoring whale activity) and mentions optional ticker filtering, plus premium vs. free access via session_token or payment. However, it does not explicitly name alternative tools or state when not to use this tool, so it stops short of full usage guidance.

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