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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, non-destructive), so the description only needs to add behavioral context. It adds the Pro/Ultimate access note and the fact that the tool returns both current and historical boards, but it does not describe pagination behavior, default limits, or what happens when history is unavailable.

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 description is short and front-loads the most important content in the first sentence. The final 'Market data: answers with numbers on Pro and Ultimate' clause is a little terse, but it carries useful access-tier information rather than being pure padding.

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 simple read-only, parameter-free card tool, the schema and annotations cover a large part of invocation. The description names the returned kind of content, but with no output schema it falls short of fully describing the shape of the returned absurdity, such as exact fields, row count limits, or how 'past boards' are included.

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 input schema already documents both parameters completely, so the baseline is 3 even though the description adds little parameter-specific meaning. The phrase 'newest reading plus past boards' loosely supports the since parameter, but the description provides no extra detail on limits or date ranges 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 clearly identifies the tool as an implied volatility board and gives concrete contents: VIX, other volatility gauges, one-year percentiles, and both current and historical boards. It is distinguishable from the sibling financial-market tools, though it does not explicitly name one or contrast itself with a specific alternatives.

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 does not state when to prefer this tool over siblings like get_market_context, get_fx_board, or get_treasury_curve. It implies the usage is 'when someone wants volatility readings,' but it gives no explicit or when-not guidance.

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