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

Beyond the readOnly/openWorld/non-destructive annotations, the description discloses substantial behavior an agent could not get elsewhere: the response is split by epistemic status (current_state recomputed in place with NO history, so joining to a past timestamp is lookahead bias; observed on an immutable capture clock), the tool publishes inputs not predictions, and the call costs $0.03 USDC on Base or is covered by a plan key. This is exactly the extra context the lower annotation bar is meant to reward.

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?

It is long, but front-loaded with the core purpose and almost every clause carries distinct content (content classes, epistemic caveat, cost). The parenthetical catalogue of social measurements is the densest stretch and could be trimmed, which keeps it from a 5.

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 exists, so the description must carry the return-value burden, and it does by enumerating the feature groups and the current_state vs observed split. With annotations covering the safety profile and cost/scope communicated, an agent has everything needed to call this 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?

Schema description coverage is 100% for the single 'token' parameter (schema already documents '0x + 40 hex'), so the baseline is 3. The description adds domain scope ('Robinhood Chain token') but no format or syntax detail beyond what the schema states, so no lift above baseline.

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 opening line states a specific resource and scope: 'THE FEATURE ROW FOR A TRADING AGENT. One call returns the token-level feature row for a Robinhood Chain token.' It then enumerates the exact content classes (launch facts, activity, deployer track record, price quote, social measurements), which lets an agent tell it apart from narrower siblings like robinx_mentions or robinx_token. It stops short of naming the sibling it is not, so it does not reach a 5.

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?

Use context is implied rather than stated explicitly: 'ready to fold into your own model' and 'backtest these inputs against your own forward returns' suggest the ingestion/backtest scenario, and 'Robinhood Chain only' constrains scope. There is no explicit when-to-use-vs-alternatives guidance pointing at the ~30 sibling tools, so an agent must infer the boundary.

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