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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description still adds real value: the scoring method (ratio to SPY vs 50-day), the four state labels, the payload structure, and the free-sample truncation (5 rows, first 3 ETFs per state, one-day delay).

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 purpose is front-loaded in the first clause and nothing is padding. However, the second sentence is a single very dense run-on packing scoring, labels, and row layout, which hurts scannability.

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 must carry the return-value burden, and it does: it enumerates the instrument universe (~50 ETFs plus macro-book instruments), the state lists, the row fields (symbol, kind, label, state), and the free-sample limits. Nothing needed to interpret the response 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?

The tool takes no parameters, so the schema carries no semantics to explain; baseline 4 applies. The description correctly spends no words on inputs.

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 resource ('Sector and macro ROTATION map') and what it contains, going well beyond a restatement of the name. It implicitly differentiates from get_rotation_live via the 'free sample... one market day delayed' note, but never names that sibling, so the differentiation is left to inference.

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?

It clarifies interpretation ('A state map, not a buy list') and flags that confirmed rotation is late for a pullback buyer, which is useful framing. However, it gives no explicit when-to-use routing versus get_rotation_live, so the agent must infer that this is the delayed/sample tier rather than the live one.

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