present-valuePresent value of a single future amount discounted annually. The inverse of future-value.
| Name | Required | Description | Default |
|---|---|---|---|
| years | Yes | Number of years until the amount is received. | |
| futureAmount | Yes | Amount received in the future. | |
| annualRatePct | Yes | Annual discount rate in percent. |
| Name | Required | Description | Default |
|---|---|---|---|
| pv | No | Present value. |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows it is a safe, pure calculation. The description adds the annual discounting convention and the mathematical relationship to future-value, but does not disclose edge cases or potential pitfalls beyond what annotations and schema cover.
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 two short, front-loaded sentences. The first states the core purpose, and the second adds the inverse relationship to future-value. No wasted words.
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 financial calculator with three fully documented parameters, an output schema, and safety annotations, the description is complete. It communicates the single-amount scope and annual discounting, which is sufficient for an agent to select and invoke the tool 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?
Schema description coverage is 100%, with each parameter (futureAmount, annualRatePct, years) clearly described. The tool description adds only the 'annual discounting' nuance, which is minor; the schema already carries the parameter semantics burden.
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: computes the present value of a single future amount discounted annually. It also explicitly mentions being the inverse of future-value, which distinguishes it from related sibling tools like annuity-pv, npv, or future-value.
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 provides clear context: it is for a single future amount and the inverse of future-value. However, it does not explicitly name alternative tools for multiple cash flows (e.g., npv) or state when not to use it, so it lacks explicit exclusions.
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.
Many tools are distinct formulas, but there are overlapping families (e.g., future-value, compound-interest, contributions all handle contributions; cagr, required-return, roi all measure returns). The sheer volume of 99 tools increases misselection risk, even with clear descriptions.
All tool names are lowercase with hyphens, following a consistent pattern (verb-noun or noun-phrase). Acronyms like irr, npv, and roa are used predictably. No mixed conventions or camelCase.
99 tools is far beyond the 'extreme mismatch' threshold of 50+. While each calculator is individual, the sheer number makes the server unwieldy and likely to overwhelm agents.
The tool surface covers a wide range of financial calculations: time value of money, loans, bonds, options, depreciation, accounting ratios, FIRE, and German tax specifics. Minor gaps exist (e.g., annuity-due variants, bond yield-to-call), but the core domain is thoroughly addressed.