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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=true, so the safety profile is known. The description adds the look-back limit ('about a year') which is useful behavioral context, but does not disclose rate limits, authentication requirements beyond 'Pro', or return format specifics.

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?

Single sentence, front-loaded with the core purpose, no waste. The trailing 'Pro' is terse but possibly unclear whether it's a tagline or a requirement.

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?

Without an output schema, the description should explain the return format (e.g., array of OHLC bars with date keys). It doesn't. However, annotations cover safety and the look-back limit is given. For a read-only data retrieval tool, it's minimally adequate but leaves return shape unspecified.

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 coverage is 100%, with each parameter documented (occ example, from/to format). The description adds only minimal context: 'one option contract' and 'between two dates'. Baseline 3 is appropriate when schema is complete.

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+resource: 'Daily OHLC price bars for one option contract by OCC symbol'. Clearly distinguishable from siblings like stock_candles (single stock) and contract_chain (list of contracts).

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?

Implies usage context ('one option contract', OCC symbol required) but provides no explicit when-to-use vs alternatives, no mention of prerequisites like a Pro subscription requirement beyond the word 'Pro'. No exclusions stated.

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