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

Annotations already declare readOnly, idempotent, and non-destructive, so the safety profile is covered. The only behavioral disclosure is the look-back constraint. The unexplained 'Pro' marker and no note on data source, latency, or entitlement limits fall short of adding real context 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?

One dense sentence front-loads the resource but compresses five outputs plus a range into a single clause, and the trailing 'Pro' is an unearned token that adds no information.

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 read-only analytics tool with no output schema, the description should at least hint at return structure or data granularity; it instead leaves 'Pro' undefined and omits any output-shape guidance, leaving the agent to guess what the payload looks like.

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 100% with clear descriptions for both parameters, so the schema carries the burden; the description only restates the years range and adds no format or default nuance beyond it. Baseline 3 is appropriate.

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: monthly seasonality for a stock, enumerating the exact outputs (average/median return, hit rate, best/worst years). Sibling tools cover different data domains, so no explicit differentiation is needed, but the 'Pro' suffix is unexplained.

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 look-back range (1-25 years) is stated, implicitly signaling long-horizon analysis, but there is no when-to-use guidance, no mention of alternatives to prefer for intraday or non-calendar patterns, and no exclusions.

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