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

Annotations already cover readOnly/destructive/openWorld, so the bar is lower; the description adds genuinely useful behavioral context beyond them — free, no API key, default window, and crucially the coverage limitation that anonymized venues and unavailable feeds are excluded, so an absent wallet is not proof of absent trading. It stops short of describing pagination or rate limits, but the caveats it does disclose are valuable.

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?

Front-loads what the tool returns, then the caveats and the no-key note. Five sentences is on the long side but each carries distinct information; nothing is redundant with the title or schema.

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?

An output schema exists, so return-value documentation is not strictly required, and the description nonetheless names the returned fields. It covers caveats and access constraints well. The one omission is sibling differentiation against the other whale tools, which leaves an agent without a clear selection rule.

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 the schema already documents limit, source, and window with defaults and enums. The description only echoes the default window and the venue-address restriction, adding little beyond the schema. Baseline 3 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?

States a specific verb and resource: aggregation of identifiable large-trader wallet activity for prediction markets over a 7d/30d window. It is clear on what is produced (trade count, notional, venue attribution, timestamps). However, it never differentiates itself from the close siblings pm_data_whales and pm_data_whale_wallet, which an agent must distinguish by name alone.

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 gives implied context (market context, not a recommendation) but no explicit 'use this when' guidance or alternatives. With pm_data_whales and pm_data_whale_wallet in the sibling set, the absence of routing guidance is a real gap.

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