StudentLoan.help: federal repayment plan calculator

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

Annotations already establish that this is a read-only, idempotent, non-destructive calculation. The description adds useful behavioral context: it computes both monthly payment and total, compares against the cheapest federal plan or PSLF, lists lost federal protections, and clarifies that it does not provide lender rates itself.

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 tight sentences, front-loads the core computation, and each sentence adds useful information. The final sentence about not showing lender rates prevents a likely misunderstanding without wasting space.

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 complex 17-parameter simulation with no output schema, the description adequately explains the return values and comparison behavior. It could say more about assumptions or edge cases, but annotations and the fully documented schema cover most remaining context.

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 the structured schema already documents all 17 parameters. The description adds contextual framing around the offered APR and term, but does not meaningfully explain the many household, loan, and PSLF-related parameters beyond what the schema provides.

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: compare a lender offer with federal plans and return refinanced payments, savings comparison, and lost protections. The framing around a lender-offered APR and term distinguishes it from a general federal repayment-plan comparison tool.

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?

It clearly establishes the triggering context: the user has an APR and term offered by a lender. However, it does not explicitly state when to use this instead of compare_repayment_plans or get_plan_rules, nor does it list exclusions.

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

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds genuinely new context: the results are projections, not authoritative determinations ('Estimates only'), and the math matches a named external calculator, which signals reproducibility. It does not cover input-validation failures or edge cases such as what happens with unsupported loan types.

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?

Purpose is front-loaded in the first clause, and the output enumeration is dense but each item is distinct and useful. The trailing two sentences ('Same math as...', 'Estimates only.') are short and earn their place as provenance and disclaimer.

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 14-parameter tool with no output schema, listing the returned figures (first payment, total paid, payoff years, forgiveness, cheapest plan, PSLF) is exactly the missing information an agent needs. What remains unstated is minor: nothing about computation cost, whether any plan can be omitted from results, or how private loans are treated in the comparison.

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% and already explains every enum, default and bound, so the baseline is 3. The description's references to loan dates gating plan availability and PSLF timing for government/501(c)(3) workers restate what the schema's employer and loan_dates descriptions already say, adding little beyond it.

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?

States a specific verb and resource ('Estimates each federal repayment plan') and enumerates the exact outputs it computes, so an agent knows precisely what it gets back. Siblings (get_plan_rules, compare_refinance_offer) are not named or contrasted, so differentiation is left to inference.

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 when-to-use, when-not-to-use, or alternative routing. Nothing tells the agent to prefer get_plan_rules for authoritative plan rules or compare_refinance_offer for private refinancing, so the boundary between the three tools must be guessed from names alone.

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

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuine value beyond them by disclosing the return contents (formulas, dates, limits, statutory/regulatory citation, page link) and the source of truth, which lets an agent judge whether the output is authoritative enough to cite. It stops short of noting staleness or that the rules are snapshot/point-in-time reference data.

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?

Two sentences, front-loaded with the purpose and followed by the return shape and the optional-parameter behavior. The enumeration of eight plan topics is somewhat listy but maps directly to the enum values and is therefore informative rather than filler.

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?

With one optional parameter, no output schema, and full annotation coverage, the description does the needed work: it explains what comes back and where the rules originate. The only gap is a lack of any statement about data freshness or effective dates for time-sensitive items like SAVE's end and the 2026 poverty guidelines, which an agent citing these rules would want to know.

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 coverage is 100% and the single enum parameter is fully documented with all eight allowed values, so the schema carries the semantics and the baseline of 3 applies. The description adds only a marginal note about omitting the topic. That note also diverges slightly from the schema, which says omitting returns 'a one-line summary of each' while the description says 'the list of topics,' a small ambiguity about what the no-argument call actually yields.

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: it returns the published rules (formulas, dates, limits) behind each named federal repayment plan, plus the statute/regulation and a page link. It enumerates the covered topics, which concretely bounds the scope. Sibling differentiation is only implicit — it is clearly the reference-lookup tool rather than compare_repayment_plans or compare_refinance_offer, but no sibling is named.

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?

Usage context is implied by the source framing ('as studentloan.help states them') and by the 'Omit topic for the list of topics' line, which tells the agent how to start exploring. There is no explicit when-to-use vs. when-not statement and no mention of the comparison siblings, so an agent must infer that this is for looking up rules, not for evaluating a borrower's options.

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