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

With no annotations, the description carries the full burden. It does disclose a genuine behavioral trait not in the schema: 5- and 15-minute crypto markets are filtered out, plus the return fields (trader name, outcome, price, USD size). It omits read-only nature, auth needs, rate limits, and pagination behavior.

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?

Two compact sentences that front-load the core scope, then the filtering rule, then the sibling pairing. Every clause contributes; sizing is appropriate for the tool's simplicity.

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 output schema, the description compensates by enumerating the return fields and noting the crypto-market exclusion. For a two-optional-parameter read tool this is nearly sufficient, though the absence of any read-only/safety statement is a minor gap given the lack of annotations.

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?

Schema description coverage is 100%, so both parameters are already documented (min as USD size, limit as 1–50). The description only echoes 'above a size you choose' and adds no format, default, or range detail beyond the schema, so the baseline 3 applies.

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 states a specific verb and resource: 'the largest recent buys and sells across all markets above a size you choose,' with the returned fields named. It clearly identifies the tool as a whale-trade feed, but it does not differentiate itself from closely named siblings like skilled_whales, smart_money, or top_traders, leaving an agent to infer the distinction.

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 offers a usage hint by recommending pairing with /v1/wallet to assess a whale, and implies the size threshold is user-chosen. However, there is no explicit when-to-use versus siblings (e.g., whales vs skilled_whales), and no stated exclusions beyond the crypto-market filter, so guidance is only implied.

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