Dividends and splits

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and external-data profile is covered. The description adds that the data is historical (dividend and split history) and scoped to a Yahoo symbol, which is useful but not rich behavioral detail. It does not describe output shape or ordering, though an output schema exists to carry that. A 3 is fair given annotations do the heavy lifting.

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?

One sentence, front-loaded with the verb and resource, containing zero filler. Every word earns its place, and there is no redundancy with the schema or annotations. Ideal economy of expression.

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 single-parameter, read-only historical data tool with a 100% covered schema and a present output schema, the description is nearly complete. The task of return-value explanation is delegated to the output schema, which is acceptable. The only minor gap is the absence of usage routing relative to siblings like get_history, but nothing an agent needs to call the tool correctly is missing.

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 single parameter 'symbol' is fully documented in the schema (including maxLength, ISIN support, and the fallback to 'search' for company names). The description adds no syntax, format, or constraint detail beyond what the schema already provides. Baseline 3 is correct when schema coverage is high.

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?

Clear verb+resource: 'Get the dividend and stock-split history for a Yahoo symbol.' The scope (dividends and splits, historical) is specific enough for an agent to distinguish from siblings like get_quote or get_history, though it does not name those alternatives explicitly. This is a solid, specific purpose statement that needs no further decoding.

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 usage (fetch dividend/split history for a given symbol) but offers no explicit when-to-use vs when-not-to-use guidance. It does not tell the agent to prefer get_dividends over get_history when only dividend/split data is needed, nor does it state the conditions that make this the right call. Adequate but thin.

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