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

Annotations already cover the safety profile (read-only, idempotent, non-destructive, open-world), so the description does not need to restate those. It adds useful behavioral context beyond annotations by clarifying that prices are end-of-day rather than live and that closes are split- and dividend-adjusted, plus a 'not investment advice' disclaimer.

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 front-loaded with the core resource and return contents, followed by two short scoping sentences. It is dense but appropriately sized for a data-retrieval tool with many returned fields; the closing disclaimer earns its place by preventing misuse as investment advice.

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?

An output schema exists, so the description need not explain return formatting, and annotations already carry the safety profile. For a two-parameter read-only price tool, the description supplies the key context an agent needs: EOD timing, adjustment treatment, non-live nature, and a usage disclaimer.

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 both parameters, including the ticker example and the 1-to-730 days range. The description adds only that daily bars cover 'the period you choose,' which is marginal beyond the schema and does not provide additional format or constraint detail.

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 names the specific resource (end-of-day stock prices) and enumerates the exact data returned: OHLCV, multi-period percentage changes, 52-week range, average volume, and daily bars. It also distinguishes itself from live quote tools by stating 'Not live quotes,' so an agent can identify it without opening the schema.

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 the tool is for historical/daily equity price data and explicitly excludes live quotes, which helps scope usage. However, it does not name alternatives such as company financials or other price tools, nor does it give explicit when-to-use guidance beyond the 'Not live quotes' exclusion.

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