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

With no annotations, the description must carry the transparency burden. It discloses the output fields (start rate, end rate, absolute change, percent change) and implies a read-only operation via 'Returns'. However, it does not mention important behaviors such as silent omission of invalid symbols, which is only covered in the schema parameter description, not in the tool description 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 a single sentence that is front-loaded with the core action and lists the specific output fields. Every word earns its place; there is 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 query tool with no output schema, the description sufficiently explains the return values and inputs. The schema covers the key edge case (invalid symbols omitted). The only minor gap is not mentioning date format or any limitations, but these are either in the schema or low-risk for a read-only fluctuation query.

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 67% (symbols and startDate have descriptions; endDate refs startDate). The tool description adds minimal parameter context ('one or more commodity symbols', 'start and end date') but does not compensate for the 33% gap with format details. The schema already provides the example and invalid-symbol behavior, so the description adds marginal value.

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 ('Returns') and identifies the resource ('commodity symbols') and the precise computation ('changed between a start and end date: start rate, end rate, absolute change, and percent change'). This clearly distinguishes it from sibling tools like get_latest_rates or get_time_series.

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 use case (calculating price changes over a period) but does not explicitly state when to choose this tool over siblings or provide exclusions. It lacks references to alternatives like get_historical_rates for raw history or get_latest_rates for current prices.

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 carry the full burden. It implies a safe read-only operation ('latest rate') but does not disclose any potential limitations such as default quote currency, rate update frequency, or response format. It adds some context by mentioning the shortcut nature, but lacks richer behavioral detail.

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, well-structured sentence that front-loads the core purpose and immediately gives a usage hint. No wasted words or redundancies.

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 tool's simplicity (one optional parameter, no output schema), the description covers the essential purpose and usage distinction. It falls short of a 5 because it omits explicit note about the default quote currency or return value shape, though these are not critical for selection or 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?

The schema already provides 100% coverage for the single 'quote' parameter, including its optionality and premium restriction. The tool description adds no additional parameter semantics, so the baseline of 3 is appropriate without any value added.

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 verb ('get') and resource ('latest gold (XAU) rate'). It also distinguishes itself from the sibling tool 'get_latest_rates' by positioning itself as a shortcut that does not require a symbols list, making it immediately clear what this tool offers.

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 'without needing to pass a symbols list' explicitly signals when to use this tool and implies the alternative 'get_latest_rates' which requires that list. However, it does not explicitly state exclusions (e.g., 'do not use if you need other currencies'), earning a 4 rather than 5.

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 adds valuable behavioral context by disclosing the data availability start date (1990-01-01) and the fallback to the nearest date when the exact date has no rate. This goes beyond a simple 'returns rates' disclosure, though it does not detail response format or error handling.

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 with no fluff. Front-loaded with the core action ('Returns open/high/low/close rates'), then adds two key behavioral notes. Every sentence earns its place.

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 two-parameter tool with no output schema, the description covers the essential aspects: what it returns, which symbols/date, data availability, and the fallback behavior. The schema fills in parameter details, making this a complete description for the tool's complexity.

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% so baseline is 3, but the description enriches the date parameter by explaining the date range and fallback behavior, adding meaning beyond the format-only schema. The symbols parameter is mentioned as 'one or more symbols' in the description, though the schema already covers comma-separated format.

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 returns OHLC rates for symbols on a specific historical date, which is a specific verb+resource+scope. It distinguishes itself from siblings like get_latest_rates and get_time_series by emphasizing 'past date' and 'nearest available date' fallback.

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 for when to use this tool (historical lookups on a specific date) and implicitly contrasts with "past date" vs. likely "latest" or "time series" siblings. However, it does not explicitly name alternatives or state when not to use it, which would earn a 5.

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?

Without annotations, the description carries the burden of behavioral disclosure. It reveals that rates may lag up to 10 minutes depending on plan, which is a key behavioral trait. It also notes the Premium/Plus-only restriction for quote conversion. It does not describe error handling or response format, but the disclosed lag and plan restrictions add meaningful 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 two sentences, front-loading the primary purpose and then adding relevant caveats (lag, quote usage). Every sentence provides value and there is no redundancy or 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?

The description covers the core function, data freshness caveat, and plan-based restriction, while also pointing to the sibling list_symbols tool for valid inputs. It does not describe the return format or error handling, but given the tool's simplicity and the explicit reference to related tools, this is reasonably 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 coverage is 100%, so the baseline is 3. The description's mention of 'gold, silver, crude oil' provides real-world context but the schema already includes concrete example symbols. The quote parameter's plan restriction is already in the schema description, so the description adds minimal additional semantic value 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 uses a specific verb+resource construction: 'Returns the latest rates for one or more commodity symbols.' It clearly identifies the tool's scope (latest rates, multiple symbols) and provides examples (gold, silver, crude oil), making it easy to distinguish from siblings like get_historical_rates and get_fluctuation.

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 references the list_symbols tool for valid values and mentions the quote parameter's plan restriction, but it does not explicitly state when to prefer this tool over alternatives like get_gold_price or get_time_series. Usage context is implied by 'latest rates' but no when-not-to-use guidance is given.

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 behavior, but it only says 'shortcut' and 'latest silver rate.' It does not mention the default quote behavior, response structure, or plan limitations that apply to the quote parameter, leaving meaningful gaps for an agent.

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 efficiently conveys purpose and the key differentiator without redundant or filler content.

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 one-parameter tool this captures the core operation, but without an output schema or annotations it leaves unspecified details such as the default quote currency and the shape of the returned rate, so it is adequate yet 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?

The only parameter, quote, is fully documented in the input schema, including the Premium/Plus-only restriction, so the description adds no parameter-specific meaning beyond what the schema already provides. Baseline 3 applies because schema coverage is 100%.

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 the tool provides the latest silver (XAG) rate and frames it as a shortcut that avoids passing a symbols list, distinguishing it from general rate tools like get_latest_rates and aligning with the analogous get_gold_price 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 communicates when to use the tool—when only the latest silver rate is needed and a symbols list is undesirable. It implies an alternative (the general latest-rates tool) but does not name it explicitly or list when not to use this tool.

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. It discloses the daily frequency and the 1-year maximum range, which are useful behavioral traits. However, it does not explain what happens on errors, missing data, or how invalid symbols are handled (though that is covered in the schema parameter description).

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 sentences, front-loaded with the core purpose, and includes the key constraint with no wasted words. Every sentence earns its place.

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 tool has 3 parameters and no output schema, the description is moderately complete but lacks explicit sibling differentiation and does not describe the return structure or error behavior. The schema covers parameter details well, but the tool description alone leaves some gaps.

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 67%, and the description adds the daily frequency and the 1-year range constraint, which are not in the schema. However, it does not compensate fully for the lack of an explicit endDate description, though the $ref provides the format. The added value is moderate.

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 returns daily historical rates for one or more symbols between two dates, which specifies the verb, resource, and scope. However, it does not explicitly differentiate from the sibling 'get_historical_rates', so it loses the point for sibling distinction.

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 clear context: use this tool to get daily historical rates for a date range, with the explicit constraint that the range cannot exceed 1 year. It does not mention alternatives or exclusions, but the context alone is sufficient to guide selection.

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 states the tool 'returns' data, which implies a read-only operation, but it does not disclose potential behaviors like response structure, error conditions (e.g., invalid key), or whether this call consumes quota. This is adequate 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?

The description is a single, front-loaded sentence with no wasted words. It conveys the essential information efficiently, which is appropriate for the tool's simplicity.

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 is simple with no parameters and no output schema, yet it clearly states what will be returned. While it does not detail the exact structure of the return value, 'current plan, quota, and usage' sufficiently covers user needs for a usage-checking tool. Slightly more detail could be added, but it is essentially 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?

With zero parameters and 100% schema description coverage (empty schema), the description is not expected to explain parameters. The baseline for zero params is 4, and the description adds no extra parameter-related information, so it maintains the 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?

The description uses a specific verb ('Returns') and identifies the exact resource ('current plan, quota, and usage for the configured CommodityPriceAPI key'). This clearly distinguishes the tool from its data-focused siblings (e.g., get_gold_price, get_latest_rates), making its purpose 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 description implies usage for checking API consumption, but it does not explicitly state when to use this tool versus alternatives. Given the sibling tools are all about market data, the use case is understandable but relies on inference rather than explicit guidance.

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 burden of behavioral disclosure. It indicates the operation is read-only ('Returns') and lists the returned fields, but does not describe response format, pagination, error behavior, or data freshness. This is adequate but not comprehensive.

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 well-structured: one sentence for purpose and returned fields, one sentence for usage guidance. No wasted words, and the key information is front-loaded.

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 parameters and no output schema, the description adequately covers the return values (category, default currency, unit) and usage context. It could be slightly more explicit about the response format (e.g., array of objects) and whether any authentication is needed, but overall it is complete enough for simple tool 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?

There are zero parameters, so schema coverage is trivially 100%. The baseline for 0 params is 4, and no parameter explanations are needed. The description adds value by explaining what the response contains, which is beyond the empty 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?

The description clearly states the tool returns all supported commodity symbols with specific fields (category, default currency, unit). It distinguishes itself from sibling rate tools by focusing on listing symbols rather than retrieving prices or rates.

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 explicitly says to use this tool to look up a symbol before calling rate tools, providing a clear usage context relative to its siblings. However, it does not explicitly state when not to use it or name alternatives, which would make it a 5.

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