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

With no annotations, the description carries the full burden. It discloses supported chains and the general nature of the results (large transfers, accumulation), which implies a read-only scan, but says nothing about auth needs, rate limits, latency, or how 'accumulation' is detected.

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 short sentences, zero filler, with the core action and return content front-loaded. Every clause earns its place.

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?

No output schema and no annotations, so the description is the only source of behavioral detail; it covers input intent and supported chains adequately but omits return structure, time window for 'recent', and result limits, which matters for a scanning tool.

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 coverage is 100% with a single documented watchlist parameter, so the baseline is 3. The description corroborates the chain enum ('Supports ETH, BTC and SOL') but adds no syntax, labeling, or batching detail beyond what the schema already provides.

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 (scans), the input resource (given addresses), and the output (recent on-chain movements such as large transfers and accumulation), so the agent knows it is a chain-activity lookup rather than a static whale list. It does not, however, distinguish itself from list_known_whales or get_wallets, leaving the sibling boundary implicit.

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 no when-to-use guidance, no prerequisites, and no mention of when to prefer list_known_whales or another activity tool instead. The only implied usage is that you must supply addresses, which the schema already enforces.

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