RentBuy.org

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

Annotations already declare this a safe, idempotent, non-destructive read. Beyond that, the description discloses the 2-10 scenario bound, that deltas are computed against the first scenario (an ordering-dependent behavior), and that each scenario is independent overrides on top of site defaults. Nothing contradicts the annotations.

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?

Three sentences, front-loaded with the operation and its return shape, then the scenario model, then the sibling routing. The enumeration of return fields is somewhat dense but each item is 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 an output schema present, the description need not explain return values, yet it still conveys the key ones. It covers cardinality limits, override semantics, delta baseline, and naming. The only minor gap is that the 40-character name limit and the 20 one-time-cost cap live only in the schema.

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?

Top-level schema description coverage is 0% for the single 'scenarios' parameter, but the description compensates by explaining the structure (independent input overrides plus one-time costs layered on site defaults) and the required 'name' semantics with concrete examples. The nested field-level docs are strong, so this adds rather than duplicates.

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 (runs 2-10 named scenarios side by side), enumerates the outputs returned, and explicitly differentiates from the sibling: 'One call replaces many rentbuy_run_scenario calls.' An agent can distinguish it from rentbuy_run_scenario and rentbuy_sweep purely from the text.

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?

Names the alternative it supersedes ('One call replaces many rentbuy_run_scenario calls') and gives practical naming guidance tied to the scenario-override model. It stops short of explaining when NOT to use it (e.g., when rentbuy_sweep's parametric ranges are the right tool instead of discrete named scenarios).

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 readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuine context beyond that: what the opened panel renders and that missing inputs fall back to site defaults. It does not, however, discuss any UI-state or repeated-open behavior, so it stops short of full disclosure.

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?

Four tight sentences, front-loaded with the capability, then the trigger, then parameter guidance, then the alternative. No sentence is redundant and nothing important is buried.

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?

An output schema exists, so return values need no explanation, and the annotations carry the safety profile. The description covers capability, trigger conditions, parameter sourcing, default behavior and sibling routing, which is everything an agent needs to select and invoke it 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%, so the nested inputs and oneTimeCosts fields are already fully documented. The description still adds operational meaning by telling the agent to pass the inputs and one-time costs from the scenario under discussion and that omitted inputs use site defaults, which goes slightly beyond the schema baseline.

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 ('Opens an interactive rent-vs-buy calculator') and even enumerates the panel contents (editable inputs, net-worth charts, year-by-year report, Monte Carlo analysis). This clearly distinguishes it from siblings like rentbuy_run_scenario and rentbuy_sweep, which compute without opening a panel.

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?

Gives explicit when-to-use ('when the user wants to see or adjust a scenario') and when-not ('Use the other rentbuy tools for calculations, comparisons and sweeps without opening a new panel'). The routing between opening a panel and running a calculation is unambiguous.

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, so the safety profile is covered. The description adds genuinely useful behavior: the partial-input contract (unspecified fields fall back to site defaults) and the detail flag's effect on the response size. It does not cover runtime/rate considerations, but for a deterministic local model none are expected.

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?

Three tight sentences, front-loaded with what the tool does and what it returns, then the input contract, then the sibling routing. No filler and no repetition of schema detail.

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?

Covers purpose, input convention, output toggling and alternative tools, which is everything an agent needs for a 3-param tool with a fully documented nested schema and an output schema. Nothing material is missing.

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 each input documents units, ranges and defaults, so the schema does the heavy lifting. The description only restates the partial-input convention and the 'yearly' detail mode, both of which the schema already states. Baseline 3 is appropriate.

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+resource+scope: 'Runs one 30-year rent-vs-buy comparison with the rentbuy.org model.' It also enumerates what comes back (winner, net worth at year 30, break-even year), which an agent can use to distinguish it from the batch siblings.

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?

Gives explicit operating instructions ('Give only the inputs you want to change; everything else uses the site defaults') and names the alternatives with the condition for switching: 'Use rentbuy_compare_scenarios or rentbuy_sweep instead of calling this repeatedly.' This is textbook when-to-use routing.

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 the description adds real behavior beyond them: outputs are buyer-minus-renter net worth at year 30 after selling costs, interpolated crossover only exists for single-parameter sweeps, and the grid is capped at 50 steps per axis / 400 total grid points. It also discloses the fallback semantics ('other inputs come from base or the site defaults'), which the schema does not state.

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?

Four sentences, front-loaded with what the tool computes before stating input requirements and then use cases. The opening sentence is dense with output enumeration that partly duplicates the output schema, but nothing is filler and the ordering follows what an agent needs first.

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 nested-object, two-axis sweep tool with an output schema and full safety annotations, the description supplies the missing glue: fallback defaults, grid limits, the values-vs-min/max mode, and the single-axis-only crossover. An agent has everything needed to invoke it correctly; return-value description is redundant given the output schema but harmless.

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?

With 75% schema coverage the baseline is 3, and the description earns above that by stating the either/or input mode ('give values[] or min, max and steps') and the 400-grid-point ceiling — relationships absent from the schema, which only bounds individual fields. It does not explain units or the parameter enum semantics, but those are already documented in 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?

Opens with a precise verb and scope — 'Varies one input (or a grid of two) across a range' — and enumerates exactly what it returns (net worth at year 30 after selling costs, winner, break-even year, crossover). The 'sensitivity questions such as ...' framing makes it clear this is not the single-scenario tool, so an agent can tell it apart from rentbuy_run_scenario and rentbuy_compare_scenarios without opening a schema.

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?

Gives explicit context with two concrete motivating questions ('at what rent does buying win?', 'how does the result change with the mortgage rate?'), which effectively routes the agent here rather than to run_scenario. It stops short of naming alternatives or stating when NOT to use it (e.g., for one-off single-point answers), so it is clear but not complete routing guidance.

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