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

Annotations already declare readOnlyHint=true, covering the safety profile. The description adds valuable context beyond that: it explains the output is evidence-based (series and averages) and explicitly frames results as 'signals, not verdicts,' guiding how the AI should present them. This is a meaningful behavioral caveat not captured in 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?

The description is three sentences long, front-loaded with the main purpose, and each sentence provides unique information: what it measures, what it returns, and how to interpret it. No redundancy or filler.

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 single-parameter read-only tool with an output schema, the description thoroughly covers what the tool does, what metrics it returns, and how the results should be interpreted. It is complete enough for an agent to select and invoke it correctly.

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 only parameter, ticker, is already well-documented in the schema with a description (e.g., case-insensitive). The tool description does not add additional semantic meaning about the parameter beyond the schema, so with 100% schema coverage the baseline of 3 applies.

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 states what the tool does: it returns ROIC/ROE against cost of capital and share count changes, with year-by-year series and averages. This specific verb+resource combination effectively distinguishes it from sibling tools like get_intrinsic_value or get_expected_return.

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 implies the tool is for assessing business quality via the opening question 'Is this a good business?' but does not explicitly state when to use it over alternatives or when not to use it. The note about 'signals, not verdicts' is more about presentation than usage context.

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