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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: it returns both quote data and greeks, includes intrinsic/extrinsic value, and supports live/delayed quotes. It does not disclose rate limits, data source latency, or what 'delayed' means, but the annotations carry the main safety burden and the description adds meaningful detail beyond them.

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 two sentences plus an example, with no wasted words. The core purpose is front-loaded, the return fields are listed compactly, and the example is directly useful. Every sentence earns its place.

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 single-quote tool with 100% schema coverage and no output schema, the description is nearly complete. It covers what the tool returns, how to identify the contract, and provides a working example. The only gap is that it doesn't explain the optional 'date' parameter for historical quotes, which is documented in the schema but not in the description. Given the tool's simplicity, this is a minor omission.

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%, so the schema already documents all three parameters. The description adds an example with a concrete OCC symbol and explains the return fields, but it does not add meaning beyond the schema for the parameters themselves. The example is helpful for formatting the optionSymbol, but the schema already provides that format. Baseline 3 is appropriate.

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 ('Get'), a precise resource ('a live/delayed quote plus greeks for a single option contract'), and the key identifier ('OCC option symbol'). It clearly distinguishes itself from sibling tools like marketdata_option_chain (which would handle multiple contracts) and marketdata_stock_quote (which handles equities).

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 implies usage by specifying the input format and providing an example call. It does not explicitly state when to use this tool versus marketdata_option_chain or marketdata_candles, but the 'single option contract' scope and the example make the primary use case clear. The optional 'date' parameter for historical quotes is mentioned in the schema, not the description, so the description itself lacks explicit when-to-use guidance for historical vs live.

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