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

With no annotations, the description carries the full burden and does so: it discloses that only derived fields are returned, that the reference quote is excluded, that sampling runs every 5 minutes including while US markets are closed, and that each response carries a timestamp, data age, and stale flag. It also flags the 24-hour trailing statistics, so the agent knows both the freshness semantics and the payload shape.

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 front-loaded with the resource and coverage before moving to caveats, and every clause carries information (coverage list, derived-only caveat, staleness fields, 24h stats, non-execution disclaimer). It is dense but slightly long, with the symbol enumeration taking substantial space for low decisional value.

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?

There is no output schema, yet the description compensates by enumerating the returned fields, the staleness metadata, and the per-symbol 24-hour statistics. For a zero-parameter read tool, an agent has everything needed to call it and interpret the result without further documentation.

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?

The tool takes zero parameters, so the baseline is 4 and there is no parameter meaning for the description to add. The schema is empty and fully covered, leaving nothing ambiguous.

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 names a specific resource (Robinhood Chain stock-token spread snapshot), the chainId, the exact 12 symbols covered, and the three data elements returned (v3 pool price, v4 cross-check, USD liquidity, spread vs reference). This is far more than a restatement of the name and lets an agent decide relevance immediately.

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 supplies an explicit usage boundary: 'For monitoring and research, not an execution feed,' which tells the agent not to rely on it for trade execution. It does not, however, mention the sibling rh-stock-spread-history or state when to prefer the historical variant over this snapshot, leaving that distinction to inference from 'Latest'/'snapshot'.

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