size_loanSize an apartment loan the way a lender does: the lowest of the LTV, DSCR and debt-yield limits.
| Name | Required | Description | Default |
|---|---|---|---|
| noi | Yes | Net operating income, dollars per year | |
| rate | Yes | Interest rate, percent (6.25) | |
| amort | No | Amortization, years | |
| value | Yes | Appraised value, dollars | |
| max_ltv | No | Maximum LTV, percent | |
| min_dscr | No | Minimum DSCR, multiple (1.25) | |
| min_debt_yield | No | Minimum debt yield, percent; 0 if not tested |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this as a safe, read-only, idempotent calculation. The description adds real behavioral context by explaining the lender-style method—taking the minimum of LTV, DSCR, and debt-yield constraints. It still doesn't mention defaults for optional parameters or what happens if they are omitted.
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?
A single, front-loaded sentence with no wasted words. It communicates the tool's purpose and calculation logic efficiently.
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 full schema coverage and safe-operation annotations, the description is nearly complete. The only gaps are that it does not state the return value explicitly or explain how optional parameters are defaulted.
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 description coverage is 100%, so all seven parameters are already documented. The description adds no parameter-specific meaning beyond confirming the three constraint types correspond to max_ltv, min_dscr, and min_debt_yield.
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 states a specific verb and resource ('Size an apartment loan') and clarifies the calculation method: the lowest of LTV, DSCR, and debt-yield limits. It is easy to distinguish from sibling tools like refinance_break_even or cash_out, though it doesn't explicitly name alternatives.
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 when to use it (when you need a lender-style loan sizing), but there are no explicit when-to-use/when-not conditions or comparisons to sibling tools. Usage is inferable but not guided.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.