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

Annotations already indicate read-only, open-world, and non-destructive behavior. The description adds useful context: fundamental inputs are not looked up, and the ticker is used only to auto-fill the current price, clarifying data sourcing and side effects beyond what annotations state.

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 dense sentences with no filler. The formula is front-loaded, and the second sentence gives the essential parameter-use guidance. It does not repeat schema details unnecessarily.

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?

The description is complete enough for a stateless calculator: it explains the model, required inputs, optional price behavior, and the margin-of-safety use case. No output schema exists, but the return value is evidently the intrinsic value per share plus a comparison when a price or ticker is supplied; an explicit return-format description would be the only minor gap.

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%, so the baseline is 3. The description adds value by grouping fcf/growth/discount/terminal/years as direct judgment calls rather than lookups, and explains that ticker/price feeds a margin-of-safety comparison. This clarifies the meaning and purpose of the parameters beyond their schema descriptions.

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 names a specific verb ('Compute') and resource ('simplified discounted-cash-flow intrinsic value per share'), and spells out the DCF approach with forward FCF projection, discounting, and Gordon terminal value. This clearly distinguishes it from sibling calculators like Altman Z or Graham Number.

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 explicitly instructs the agent to pass fcf/growth/discount/terminal/years directly as judgment calls and explains the optional ticker/price path for a margin-of-safety comparison. It gives clear context for use but does not name alternative tools or state when not to use it.

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