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

With no annotations, the description carries the full behavioral disclosure burden. It does not explain what happens when variableCostPerUnit is omitted, whether values are rounded up to whole units, what occurs if pricePerUnit <= variableCostPerUnit, or what the return format is. The formula and edge cases are entirely undisclosed.

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 concise and front-loaded with the core purpose, followed by a compact input list. It avoids unnecessary words, but the input list could have been used to add behavioral caveats rather than merely repeating schema properties.

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 tool with no annotations, no output schema, and four parameters with minimal schema documentation, the description is incomplete. It does not explain the calculation formula, defaults for optional parameters, return type, or constraints, leaving an agent to guess critical operational details.

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?

The description lists parameters and marks targetProfit as optional, but it also implies variableCostPerUnit is required by not marking it optional, contradicting the schema which lists only fixedCosts and pricePerUnit as required. It adds minimal meaning beyond the schema (which has 0% description coverage) and does not explain each parameter's role or default behavior.

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 exactly what the tool does: 'Calculate break-even point in units.' The verb 'calculate' and the specific resource 'break-even point in units' are unambiguous, and this clearly distinguishes it from the fee and margin calculators among its 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?

There is no guidance about when to use this tool versus the sibling calculators. It only lists inputs, with no mention of scenarios (e.g., 'when you need to know how many units to sell to cover fixed costs'). No exclusions, prerequisites, or alternatives are named.

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?

There are no annotations, so the description carries the full behavioral burden. It discloses the core behavior, the optional monthly contribution, and the compoundFreq default of 12. However, it does not specify the exact return value, whether contributions are applied at the start or end of each period, or how rounding is handled.

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 compact sentences convey the formula scope and all input parameters with no wasted wording. The parameter list is front-loaded and easy to scan.

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?

The definition covers the parameters and a key default, and there is no output schema to document the result. Still, it omits the output format, the default for monthlyContribution, and any usage context, leaving minor but real gaps for an agent.

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 0%, so the description compensates by listing all five parameters, clarifying that annualRate is a percentage, and giving compoundFreq a default of 12. It does not fully explain compoundFreq as 'times per year', but the name and default make the intended meaning inferable.

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: it calculates compound interest with optional monthly contributions. This clearly differentiates it from the sibling fee, discount, margin, and loan calculators by naming the exact financial operation.

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 intended use is implied by the name and description: use this when compound interest or contribution growth is needed. However, there is no explicit when-to-use or when-not-to-use guidance, nor any mention of alternatives like loan_calculator for amortizing calculations.

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?

With no annotations, the description must disclose behavioral nuances, but it only states the calculation outcome. It does not clarify whether discountPercent should be expressed as 20 or 0.2, how rounding is handled, or whether currency formatting applies to originalPrice and the result.

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 short and front-loaded, with the core action in the first sentence. The 'Input:' line is somewhat redundant given the schema, but it provides a quick explicit summary without bloating the description.

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 straightforward two-parameter calculator, this is minimally viable: the purpose and input names are clear. However, without an output schema or annotation, the missing details about percent format, rounding, and return structure leave noticeable gaps for a fully informed invocation.

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 0%, so the description must compensate. It merely repeats the parameter names and adds 'discount %', leaving originalPrice's currency/units and discountPercent's accepted range (e.g., 0–100 vs 0–1) undocumented.

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 uses a specific verb ('Calculate') and names the exact resource: final price and savings derived from a discount percentage. This clearly distinguishes the tool from sibling calculators like fee, margin, and loan calculators, even without explicit sibling comparisons.

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 guidance is provided about when to use this calculator versus alternatives such as markup_margin_calculator or sales_tax_calculator. The description states what the tool does but gives no context for selecting it among the many sibling calculators.

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?

With no annotations, the description carries the burden of disclosing behavior. It usefully states that the calculation includes a final value fee plus a $0.35 payment processing fee, but it does not clarify whether shipping is included, whether fee rates vary by market, what currency the output is in, or what the return value represents.

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 sentences with no filler. The core purpose and market scope are front-loaded, and the fee-composition detail directly follows in the second sentence.

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 no output schema, no annotations, and 0% schema description coverage, the description leaves important gaps: it does not specify the output format, the role of the shipping parameter, or the fee-rate assumptions per market. An agent could not confidently determine the correct inputs or expected result from this description alone.

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 0%, so the description must explain the parameters. It indirectly covers the market enum by listing US/UK/DE/CA/AU, but it does not explain itemPrice, shipping, or how the formula maps to those inputs. This is only minimal compensation for the schema gap.

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 the tool calculates eBay fees and identifies the applicable markets (US/UK/DE/CA/AU). It is specific enough to distinguish eBay from sibling calculators like etsy_fee_calculator or paypal_fee_calculator, though it does not explicitly name a sibling alternative.

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 guidance is given on when to use this tool versus the many sibling calculators, or when another tool would be more appropriate. The market list implies scope but does not help an agent choose between eBay and PayPal or Etsy fee calculations.

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?

No annotations are provided, so the description must disclose behavioral traits. It reveals the fee formula, which is useful, and implies a pure calculation with no side effects. However, it doesn't explicitly state that it is read-only, nor does it mention any limitations (e.g., currency, rounding, or whether shipping fees are included in the calculation). The disclosure is adequate but not exhaustive.

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 a single, information-dense sentence followed by a brief EU addition. It front-loads the purpose and fee breakdown, and every clause adds value. No fluff or repetition.

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 calculator with no output schema and no annotations, the description covers the core formula and the EU variant, but leaves gaps: it doesn't specify what the output represents (likely total fees), the currency, or how shippingFee is treated. An agent might call it correctly, but some assumptions are required.

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 0%, so the description must compensate. It mentions itemPrice implicitly via the fee breakdown and country via the EU note, but it never explains the role of shippingFee or explicitly maps each parameter to its meaning. The agent is left to infer that itemPrice is the sale price and that shippingFee may or may not affect fees, which is a significant gap.

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 a specific action (calculate Etsy fees) with the exact fee components (transaction, payment processing, listing, EU regulatory). It distinguishes from sibling fee calculators by naming the platform and the fee structure, making it unambiguous.

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 context is explicit: this tool is for Etsy fees. While it doesn't explicitly say 'use this instead of other calculators' or exclude other platforms, the description's specificity to Etsy provides clear context for when it applies. No exclusions are stated, but they aren't strictly needed given the name and description.

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?

With no annotations, the description carries the full burden, but it discloses almost nothing beyond the basic calculation. It does not state assumptions (e.g., interest compounding method, amortization), edge cases, or that it is a pure read-only calculation. An agent cannot anticipate limitations or side effects.

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 sentences with no wasted words, which is structurally clean. However, it is so sparse that it borders on under-specification rather than being appropriately concise. It could be slightly expanded without losing efficiency.

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 absence of annotations, an output schema, and parameter descriptions, the tool is seriously under-specified. An agent would not know the return format (e.g., numeric payment amount), any constraints on inputs (e.g., positive values), or the underlying formula. This is insufficient for reliable invocation.

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 0%, so the description must compensate. It lists the three inputs and notes annualRate is in percent, but it does not define principal (currency units?) or years (integer or decimal?), nor explain the relationship between parameters. This adds minimal meaning beyond the parameter names.

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 the tool computes a fixed-rate loan's monthly payment, naming the resource (loan) and the output (monthly payment). It is specific enough to distinguish it from fee calculators, but it does not explicitly differentiate from the sibling mortgage_calculator, which could be seen as overlapping.

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 gives no guidance on when to use this tool versus alternatives. It does not mention conditions like 'use for fixed-rate loans only' or compare with mortgage_calculator or compound_interest_calculator. The context is implied but not explicit.

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?

With no annotations, the description carries the full burden of behavioral disclosure. It communicates that this is a pure calculation tool ('Calculate... from cost + markup %'), but it does not clarify whether the returned margin is a percentage or dollar amount, nor does it disclose any formula, rounding, or edge-case behavior.

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 a single efficient sentence plus a compact input reminder. Every word contributes: the verb, the outputs, the input relationship, and the parameter list. No filler or redundant information is present.

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 low-complexity, two-parameter calculator, the description covers the main concerns: what it calculates, from what inputs, and what the outputs are. It is slightly incomplete in not specifying the margin's return format or formula, but the core selection and invocation needs are met.

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 0%, so the description must compensate. It restates both parameter names and adds one useful hint by calling markupPercent 'markup %', implying it is a percentage. However, it does not specify expected formats (e.g., 25 vs 0.25) or explain how the inputs map to the two outputs, leaving some ambiguity.

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 opens with a specific verb ('Calculate') and names the exact outputs ('selling price and margin') plus the required inputs ('cost + markup %'). This makes the tool's purpose unmistakable and distinguishes it from the profit_margin_calculator sibling by anchoring it to markup percentage rather than margin ratio.

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 phrase 'from cost + markup %' conveys the clear usage context: use this tool when you have cost and a markup percentage and need selling price or margin. It does not explicitly name alternatives or state when not to use it, but for a simple calculator this context is sufficient.

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?

With no annotations, the description carries the disclosure burden. It provides defaults and units for inputs and states the output as 'monthly mortgage payment,' but it does not disclose the calculation formula, rounding behavior, or any input constraints (e.g., downPayment percentage range).

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 a single efficient sentence, front-loaded with the output and followed by compact parameter details. Every word contributes value with no repetition.

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?

The description is sufficient for invoking the tool: it lists all required and optional inputs with defaultsable. However, the absence of an output schema means the exact return format (e.g., formatted number vs. detailed breakdown) is not specified, and invalid input handling is unaddressed.

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 0%, so the description must compensate. It names all four parameters with units and defaults: homePrice, downPayment (%) default 20, years default 30, annualRate (%) default 6.5. This fully clarifies the schema's bare parameter definitions.

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 the tool's purpose: 'Monthly mortgage payment.' This identifies the output resource and the domain. However, it does not explicitly differentiate from the sibling loan_calculator, which could serve a similar purpose.

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 purpose is implied by the name and description: use for mortgage payment calculations. There is no explicit guidance on when to choose this tool over sibling calculators like loan_calculator, and no exclusions are provided.

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?

With no annotations provided, the description carries the full behavioral disclosure burden. It does disclose the core fee formulas, which is useful behavioral information. However, it does not mention what the tool returns (fee amount vs. total), currency assumptions, rounding behavior, or how the isMicropayment flag affects the calculation beyond the rate. This is partial transparency.

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 a single concise sentence that front-loads the most important functional information: the fee rate formulas. There is no wasted wording, and every piece of content adds value for an agent trying to calculate a PayPal fee.

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?

This is a simple calculator with two parameters and no output schema, so the description is not required to be extensive. However, it lacks explicit return-value semantics, currency/unit clarification, and clear parameter-to-rate mapping. The core rate information is present, making it barely adequate for correct invocation, but not fully complete.

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 0%, so the description must compensate for the bare number/boolean schema. It explains the two rate tiers and implies that isMicropayment selects between them, adding meaning beyond the schema. However, it does not explicitly map 'domestic 2.99%+$0.30' to amount/isMicropayment, nor does it clarify units or default behavior for isMicropayment.

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 communicates that this tool deals with PayPal fees and specifies the domestic and micropayment rate structures, which makes the resource clear. It lacks an explicit verb like 'calculates', but the tool name and rates make the purpose inferable. It does not explicitly differentiate from sibling fee calculators beyond the name, so it falls short of a 5.

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 usage for PayPal domestic or micropayment fee calculations, but it does not explicitly say when to use this tool versus alternatives like etsy_fee_calculator or stripe_fee_calculator. It also does not state exclusions such as international transactions. The usage context is only implied by the name and the two rate categories.

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?

No annotations are provided, so the description must convey behavioral traits. It indicates a pure calculation (compare net revenue) but does not explicitly state that it is read-only or non-destructive. It also does not describe any side effects, authentication needs, or rate limits. For a calculator, this is likely acceptable, but the description could be clearer about being a computation without external effects.

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 a single, front-loaded sentence that states the core purpose and lists the parameters. There is no redundant information, and it is appropriately short.

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?

The tool lacks an output schema, so the description should explain what the tool returns. It only says 'Compare net revenue' without specifying the format (e.g., a list, a table, a recommendation). It also does not mention any edge cases, currency assumptions, or what happens with invalid input. Given the lack of an output schema, this is a significant gap for the agent to know what to expect.

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?

The schema has no descriptions for parameters (0% coverage). The description adds that the input is 'itemPrice, shippingFee (optional)', which clarifies that shippingFee is not required and that both represent monetary values for a sale. This provides some context beyond the bare schema, but it does not explain units, formats, or how the values are used in the calculation.

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 the tool's function: 'Compare net revenue on Etsy, eBay, and PayPal for a given sale.' This is a specific verb (compare) and resource (net revenue across three named platforms), and it distinguishes itself from the sibling calculators (e.g., paypal_fee_calculator) by covering multiple platforms rather than a single one.

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 the tool is for comparing across three platforms, but it does not explicitly state when to use this tool versus the individual platform calculators. There is no mention of alternatives or conditions (e.g., 'Use this when you need to compare across platforms; use a single calculator for one platform only'). The intent is inferable but not spelled out.

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?

No annotations are provided, so the description carries the full burden. It implies a read-only pure calculation with no side effects, but it does not explicitly confirm that or disclose any edge-case behavior (e.g., handling of negative values, rounding, or return format). This is adequate for a simple calculator but not rich.

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 sentence that front-loads the action and inputs with no fluff. Every word earns its place; it is efficiently concise without being under-specified.

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 2-parameter calculator with no output schema, the description is minimal. It does not explain the formula, whether it returns both profit and margin, or any assumptions (e.g., margin = profit/revenue). An agent might need to infer the output format, creating a gap for a tool that could otherwise be fully self-explanatory.

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 0%, so the description must add meaning. It mentions 'revenue' and 'cost' but does not clarify definitions (e.g., gross revenue, total cost) or units. The names in the schema are self-explanatory, but the description adds no extra context, failing to compensate for the lack of schema descriptions.

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 ('Calculate') and resource ('gross profit and profit margin %') from revenue and cost. This clearly distinguishes it from siblings like markup_margin_calculator (which likely computes markup) and fee calculators, as it focuses on profitability metrics.

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 no guidance on when to use this tool versus alternatives such as markup_margin_calculator or break_even_calculator. It simply states what it does, leaving the agent to infer suitability without explicit context or exclusion criteria.

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?

With no annotations, the description carries the full burden of behavioral disclosure. It mentions inputs and a default tax rate, but does not state the output format (e.g., total price after tax), rounding behavior, or any side effects. The behavior is implied but not explicit.

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 extremely concise, with the core purpose front-loaded in the first clause. Every word adds value, and it includes the key input details in a compact manner.

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 calculator, the description covers the purpose and inputs, but omits explicit output details (e.g., whether it returns total or tax amount) and any edge-case behavior. Given no output schema, this gap could cause ambiguity for an agent.

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 0%, so the description must add meaning. It explains that taxRate is a percentage (%) and provides a default of 8, which goes beyond the bare schema. However, it does not clarify price's unit or format, and the description is minimal.

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 the verb ('Add') and the resource ('sales tax to a price'), making the tool's purpose unambiguous. It also implicitly differentiates from sibling calculators (discount, fees, margins) by naming a specific domain (sales tax).

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 guidance is given about when to use this tool versus the many sibling calculators. The description does not mention alternatives or conditions, leaving the agent to infer usage solely from the name and brief statement.

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?

No annotations are provided, so the description must fully disclose behavior. It only lists fee rates but does not explain what the tool outputs (e.g., total monthly fee, per-transaction fee breakdown, or both). It also doesn't mention if monthlySales is required for per-transaction fee calculation or if it's optional. The description is too sparse to convey the tool's actual behavior beyond the fee schedule.

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 a single concise sentence that front-loads the key information (monthly fees and per-transaction rates). It is efficient and to the point, with no unnecessary words. However, it could be slightly more structured (e.g., separating monthly and transaction fees) but overall it is appropriately sized.

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?

The tool has 2 parameters, no output schema, and no annotations, so the description must be robust. It only covers the 'plan' parameter's fee schedule, leaving 'monthlySales' unexplained. It also doesn't clarify what the output is (e.g., total cost, breakdown). Given the tool's purpose is to calculate fees, missing sales parameter semantics is a major incompleteness.

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?

The input schema has 0% description coverage, so the description must compensate. The description maps the 'plan' parameter to the three plans (basic/shopify/advanced) with associated fees, but it does not explain the 'monthlySales' parameter at all. This is a significant gap: the description leaves the purpose of monthlySales ambiguous, which is critical for correct invocation.

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 that this tool calculates Shopify monthly fees and lists the specific monthly and per-transaction fee rates for each plan. It is named 'shopify_fee_calculator' and the description aligns with this purpose, making it distinguishable from other platform fee calculators like PayPal or Etsy. It could be more explicit in saying 'calculates' but the fee rates make the purpose evident.

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 usage: given a Shopify plan (and optional monthly sales), it returns the fees. However, it does not explicitly state when to use this over the sibling calculators (e.g., when the merchant is on Shopify) or any exclusions (e.g., not for other platforms). The presence of sibling calculators like 'platform_fee_comparison' suggests a need for routing, but no guidance is provided.

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?

No annotations are present, so the description carries the full burden. It does reveal the fee rates, but it does not state what the tool returns (fee amount vs. total charge), what currency assumptions exist, or how the optional 'type' parameter is handled. This leaves core behavior ambiguous.

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 sentence with no filler; it front-loads the fee structure and wastes no 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?

With no output schema and no annotations, the description should clarify the return value and parameter semantics. It provides only the rate table, so an agent cannot confidently know what the tool produces or how optional parameters behave.

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 0%, and the description only indirectly maps 'domestic' and 'international' to rates. It does not define 'amount' units, explain that 'type' is optional, or specify a default; the connection between parameters and the formula is left implicit.

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 communicates the tool's domain and rates: it applies 2.9%+$0.30 for domestic Stripe transactions and 3.9%+$0.30 for international ones. It clearly distinguishes from sibling calculators by naming Stripe, though it lacks an explicit action verb like 'calculates'.

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?

There is no statement about when to use this tool versus the many sibling calculators. The only usage signal is the implied Stripe-specific scope; no alternatives, exclusions, or conditions are given.

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