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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real behavioral context beyond that: the five-complete-year lookback window, what "matched" counts, and that a current-year declared/not-declared flag is included. It omits pagination/limit behavior on a tool that returns a list.

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?

Two sentences with no filler, so length is fine, but the first is a dense verb-less noun phrase with an embedded colon list that has to be re-parsed to find the actual action. Front-loading the concept is good; the grammatical shape hurts scanability for an agent.

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 enumerates the return fields (match count, last and typical raise, declared-yet flag) and the data window, which is what an agent needs to judge relevance. Remaining gaps are the default behavior with no argument and the meaning of limit.

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 67% – month and symbol are documented in-schema, limit is not. The description mainly restates those two ("by month (1-12) or by ticker") and adds only the mild exclusivity hint. It does nothing for the undescribed limit parameter, so it neither compensates for the gap nor adds much beyond the schema.

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 defines the resource precisely: companies whose first dividend raise of the year lands in the same calendar month most years, over the last five complete years, and names the derived values returned (years matched, last/typical raise, declared-yet flag). It never names a sibling, so an agent must still infer how this differs from get_dividend_payers_by_month or get_dividend_changes. Clear purpose, weak differentiation.

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?

"Ask by month (1-12) or by ticker" gives the two entry modes, and the symbol schema says "instead of a month," implying they are alternatives. But there is no when-to-use vs. siblings, and no statement of what happens when neither month nor symbol is supplied even though all three parameters are optional. Usage is implied, not specified.

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