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

Annotations already declare readOnly/destructive/openWorld, but the description adds real behavioral context beyond them: newest-first ordering, ex-div date being the filter target, USD per-share amounts, and that future ex-dates can appear after declaration. Does not cover pagination behavior explicitly.

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?

Front-loaded with what it returns and how it's ordered, then scoping rules. Mostly tight, though the share-class/fund-series example is somewhat lengthy relative to its value.

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?

With no output schema, the description usefully explains the returned row shape (ex-div date, cash per share in USD) and the per-listing isolation rule. An agent could invoke it correctly; minor gaps remain around pagination and total-count behavior.

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 coverage is already 100%, so baseline is 3, but the description adds genuine meaning by clarifying that startDate/endDate filter on the ex-dividend date (not payment or declaration date) and that rows are newest-first (relevant to offset).

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?

States a specific verb+resource ('Get the stored declared cash dividends') with clear scope (exact stock or ETF listing) and ordering (newest first). Distinguishable from sibling lookups like GetShortInterest or GetEtfHoldings.

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?

No explicit when-to-use vs alternative guidance and no named sibling for comparison, but the scope semantics (exact listing, series isolation) implicitly tell the agent the appropriate context. Usage is implied rather than stated.

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