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

The annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds the granularity of the data (daily EOD) but does not disclose other behaviors such as date range handling, return ordering, or pagination, so it adds only minimal value beyond the annotations.

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 only two words, 'Daily EOD history,' which is extremely concise and front-loaded. While it is a sentence fragment and perhaps under-specified, it efficiently conveys the core idea with no wasted words.

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?

The description is too sparse for a tool with three parameters and no output schema. It doesn't explain return values, date range behavior, or whether prices are adjusted, leaving significant gaps for an agent trying to invoke the tool correctly.

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 has 0% description coverage for its three parameters, and the description does not explain 'to', 'from', or 'symbol'. While the parameter names are somewhat self-explanatory, the description fails to specify date formats, inclusivity, or defaults, so it does not compensate for the lack of parameter documentation.

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 'Daily EOD history,' which clearly indicates the tool provides historical end-of-day price data, and the term 'Daily' distinguishes it from sibling tools like 'intraday.' However, it lacks an explicit verb such as 'retrieves' or 'gets,' making it a clear but terse noun phrase.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention that it should be used for historical daily data while 'intraday' is for intraday data or that 'quote' is for current prices. There is no when-to-use or when-not-to-use information.

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