calculate_capm_return

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

Without annotations, the description carries the full burden. It is a calculation tool with no side effects; the description adequately states what it does but does not elaborate on output format, error cases, or permissions. It is sufficient for a simple read-only calculation.

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 concise sentences. The first sentence states the purpose, followed by the formula and an explanatory note. No redundant or filler text.

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 calculation tool, the description covers the purpose and formula. Since there is an output schema (context signal), the lack of output format description is acceptable. However, it could hint at the output type.

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?

Although schema coverage is 0%, the description includes the formula E(R)=Rf+β×(Rm−Rf), which implicitly defines the three parameters (risk-free rate, beta, market return). However, it does not explicitly describe units or valid ranges.

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 explicitly states 'Calculate expected return using CAPM', which is a specific verb and resource. It also provides the formula and explains beta implications (defensive vs aggressive), making the purpose clear and distinct from sibling tools.

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?

No explicit guidance on when to use this tool versus alternatives. The formula implies it is for CAPM calculations, but there is no mention of prerequisites or scenarios where other tools might be preferable.

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