get_historical_stock_prices

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

With no annotations provided, the description carries the full behavioral disclosure burden. It discloses the output format (specific columns), the valid parameter values, and a key constraint (intraday data cannot extend last 60 days). The mention of 'start and end' not present in the schema is a minor transparency gap but does not materially mislead.

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 well-structured with a front-loaded purpose sentence followed by a clear 'Args' block. The parameter enumerations are necessary and efficiently formatted. The 'Either Use period parameter or use start and end' line is slightly confusing given the schema lacks start/end, but overall there is no wasted text.

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 3-parameter tool with an output schema, the description provides thorough input semantics, defaults, and constraints. The existence of an output schema means return values need not be detailed further. The only notable gap is the ambiguous start/end mention, which does not significantly undermine completeness.

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?

The schema only describes the ticker parameter, leaving period and interval as bare strings. The description adds substantial meaning by listing all valid periods and intervals, defaults, and the interaction between period and start/end (even if start/end are not in the schema). This far exceeds the schema's 33% coverage and is essential for correct invocation.

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 clearly states the tool gets historical stock prices for a ticker from Yahoo Finance, enumerates the exact columns returned (Date, Open, High, Low, Close, Volume, Adj Close), and distinguishes it from sibling tools like get_stock_info (current info) or get_stock_actions (corporate actions). The verb+resource+scope is specific and 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 detailed parameter usage guidance (valid periods, intervals, default values, intraday 60-day limit) but does not explicitly state when to choose this tool over alternatives like get_stock_info or get_financial_statement. Usage is implied by the clear purpose but lacks explicit when/when-not instructions.

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