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

Beyond the read-only/idempotent/non-destructive annotations, the description discloses key behavioral constraints: signed-in connection required, keyless access refused, Free vs Starter+ return differences, the 10-coin limit, and that data is descriptive only. This is rich, non-obvious context that materially affects invocation.

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 compact and well-ordered: core action first, then usage examples, auth, plan tiers, limit, and data type. Every sentence adds information and none are redundant with the schema or annotations.

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?

Given zero parameters, a present output schema, and safety annotations, the description covers all essential invocation context: auth requirements, plan-level output differences, per-call limits, and data type. An agent has everything needed to select and call the tool correctly.

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?

There are zero parameters, so the baseline is 4. The description appropriately clarifies that the tool operates implicitly on the authenticated user's watchlist, which is the only 'input' needed. No further parameter documentation is required.

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-resource pair: running every watchlisted coin through the whale read in one call. It lists concrete outputs (flow versus normal, buy/sell lean, unusual radar) and gives example queries, making the tool's purpose unmistakable and clearly distinct from broader siblings like market_brief or whale_flow.

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 provides explicit usage phrasings ('how are my coins doing', 'anything unusual on my watchlist', 'brief me on my list') that tell an agent exactly when to select this tool. It does not name alternatives or say when not to use it, but the watchlist scoping and one-call framing make the intended context clear.

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