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

No annotations are provided, so the description carries the burden. It implies a safe read-only computation ('Compute net rental profitability') and states the return values ('net yield % and cash flow'). This is adequate for a calculator tool, though it does not explicitly declare no side effects or authentication needs.

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?

Description is concise (5 sentences) and front-loaded with core function and use case. However, the input list is partially inaccurate, which slightly detracts from structure. Overall, every sentence serves a purpose.

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 the tool has 5 parameters and an output schema, the description covers the purpose and return values. However, it fails to explain the missing parameters in the schema (vacancy %, tax bracket) and omits the notary_fees_pct parameter, making it incomplete for correct usage.

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?

While schema descriptions cover 100% of parameters, the tool description lists inputs 'vacancy %' and 'tax bracket' that are not in the schema, and omits 'notary_fees_pct'. This discrepancy misleads about required parameters and reduces the value added 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?

Description clearly states 'Compute net rental profitability after taxes and charges' with a specific verb and resource. It identifies the use case for real estate investment analysis, but does not differentiate from sibling tools like calculate_rental_yield_net, though the name hints at profitability vs yield.

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?

Description advises 'Use for real estate investment analysis' providing context, but lacks guidance on when not to use this tool versus other rental calculators (e.g., calculate_rental_yield_net). No exclusions or prerequisites are mentioned.

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