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

With no annotations provided, the description carries the full burden of behavioral disclosure. It transparently explains the calculation logic (income divided by yield, current portfolio income, and accumulation time), which is the core behavior. However, it does not mention output format, limitations, or edge cases like zero dividend yield, so it's not fully exhaustive.

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 a single, purposeful sentence that states the primary function first, then lists required and optional parameters. It is concise and well-ordered, though the opening sentence is a bit long and could be divided for even better readability.

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?

Given there is no output schema and five parameters, the description explains the core formula but does not specify the return format or how results are presented. It also doesn't address potential division by zero if dividend_yield is zero, although the schema's minimum of 0.5 provides some implicit protection. Overall, it covers the essential logic but lacks some completeness for edge cases and output structure.

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 schema already describes all five parameters with 100% coverage, so the description adds limited extra meaning. It does note that monthly_income is required and instructs the use of English parameter names, which is helpful, but it doesn't enrich understanding of each parameter beyond the schema's own 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 clearly states the tool's function: calculating the wealth needed to live off dividends, and breaks down the calculation (monthly income divided by dividend yield, current income, and time to goal). This specific verb-resource pairing distinguishes it from siblings like calculate_dividend_yield, which focuses on yield rather than the goal amount.

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 specifies required and optional parameters but does not explicitly compare with alternatives such as calculate_financial_independence or calculate_retirement. The purpose implies when to use it, but there's no when-not guidance or named sibling alternatives, so it remains at the 'implied usage' level.

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