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

Annotations already convey read-only, idempotent, open-world, and non-destructive behavior. The description adds valuable behavioral context beyond that: the Chainlink feed incorporates dividends and splits, and the feed steps at half a percent, making sub-threshold gaps noise. This helps an agent interpret results correctly.

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?

Three sentences, each earning its place: the first front-loads the full set of returned data, the second explains parameter-driven behavior, and the third surfaces a useful precision caveat. There is no fluff or repetition.

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?

For a read-only list/detail tool with one optional parameter, the description covers the returned data points and the symbol behavior adequately. There is no output schema, but the description lists the key fields. It stops short of providing exact response field names or a concrete example, which would make it fully complete.

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 input schema already documents the only parameter, symbol, with a clear example and the explicit 'leave it out' behavior, giving 100% schema description coverage. The description reinforces this by saying 'With a symbol, one stock in detail,' but it does not add meaningful semantics beyond the schema.

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 clearly identifies the resource (Robinhood stock tokens on-chain) and enumerates the returned data: last trade price, Chainlink share price with adjustments, the gap, and volume. It lacks an explicit verb like 'list' or 'get', and it does not differentiate the tool from siblings, but the intent is still unmistakable.

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 concrete invocation guidance: 'With a symbol, one stock in detail. Leave it out for every stock traded today.' This tells an agent exactly how to control the output. However, it does not compare this tool to alternatives or explain when not to use it.

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