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

Consistent with readOnlyHint=true and adds context beyond it: the data comes from the signed-in user's saved broker connection, credentials must never be passed raw, and oversized responses surface retryWith suggestions. That is meaningful behavioral disclosure, though the response shape and pagination envelope remain unstated.

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 tight sentences, front-loaded with the read-only safety statement, then narrowing advice, then overflow handling. The middle sentence is a parameter list rather than prose, but no sentence is wasted.

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 12-parameter read tool with no output schema, the description covers auth context, size-control strategy, and error/overflow recovery. The gaps (includeGreeks, brokerCredentialId, the structure of retryWith) are minor but real.

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 0%, so the description must carry the load, and it names 9 of 12 parameters as narrowing levers (expiration, expirationStart/End, strikeMin/Max, right, detailLevel, limit, page). It leaves underlyingSymbol, includeGreeks, and brokerCredentialId unexplained, and gives no format details, but it substantially compensates for the empty 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?

States a specific verb and resource: fetches option chain data from the user's saved broker connection. The resource ('option chain') is distinct enough from sibling reads like get_broker_quotes and get_broker_positions, but the description never names an alternative, so it earns a 4 rather than 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?

Gives concrete operating guidance: always narrow large requests via expiration ranges, strike bounds, right, detailLevel, limit, or page, and retry with retryWith suggestions if the response is too large. It does not address when to choose this tool over a sibling quote/position tool, so it stops short of a 5.

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