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

Annotations already mark this as readOnly and non-destructive, so the description adds no extra safety context. It does not disclose response format, rate limits, data granularity trade-offs, or other behavioral traits beyond what the schema and annotations convey. No contradiction exists.

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 short, front-loaded with the core action, and free of filler. The range list is somewhat redundant with the schema enum but serves as a useful quick reference without bloating the description.

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 simple read-only tool with a complete output schema and rich annotations, the description is mostly adequate. The main gap is the lack of explicit guidance on selecting this over stocks_get_quote, so an agent could benefit from clearer routing.

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% for all three parameters, with enums and defaults fully documented. The description's range list only duplicates the schema enum and adds no new semantic meaning 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 'Gets historical price data for a stock symbol' uses a specific verb and resource, and the word 'historical' clearly distinguishes it from sibling tools like stocks_get_quote (current quote) and stocks_search_symbol (symbol lookup). The action and object are unambiguous.

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 clear context: it is for historical price data, which implies when it should be used. However, it does not explicitly state when not to use it or directly name alternatives, so it stops short of full exclusion guidance.

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