UK Data: Money and time

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 does add a useful non-obvious cost signal (1 credit) and implies a pure read/compute operation, but it says nothing about the return shape (two rendered datetimes? offsets?), DST edge cases, or what happens with an invalid IANA zone.

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 short sentences, with the action front-loaded and the credit cost appended as a compact parenthetical. Nothing is redundant or padded.

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 three parameters, no annotations, and no output schema, the definition should say more about what comes back and how zone/DST errors are handled. The purpose and cost are covered, but an agent cannot fully predict the response from this text 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 100%, so the IANA zone and ISO 8601 semantics are already documented in the schema. The description only loosely echoes them via "ISO datetime in two time zones" and adds no format examples or constraint details beyond that 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 ("Show") and resource ("an ISO datetime in two time zones"), which is enough to distinguish it from a pure clock lookup. It does not name or contrast with the sibling time_now, so an agent must infer the boundary between 'convert this datetime' and 'get current time'.

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 explicit when-to-use guidance and no mention of alternatives such as time_now, even though that sibling is the most likely confusion point. The only cue is the implicit framing of converting an existing datetime rather than retrieving the current one.

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, and it does disclose useful non-schema facts: the data source (ECB reference data) and a cost of 1 credit. It does not say what the response contains, whether rates are ECB-daily (so non-business days may fall back), or what errors look like for bad dates/currencies.

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 resource and source, then the supported knobs, with the cost tucked into a short parenthetical. Nothing is wasted, though the parenthetical credit note slightly interrupts the parameter list.

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 4-parameter, zero-required, no-output-schema tool with no annotations, the description covers source, scope and cost but omits the return shape and edge-case behavior — both of which the agent must guess absent an output schema. Adequate but not 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 100%, so the baseline is 3; the description only restates that base, symbols and amount are optional and that any base works. It leaves the effect of 'amount' unexplained — whether it returns a converted value or a rate table — which is the one piece of meaning the schema does not convey.

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 names a specific resource (ECB reference exchange rates) and enumerates the supported variations: latest or a given date, any base, optional symbols and amount. It is unambiguous and clearly distinct from the time/holiday siblings, though it never explicitly contrasts itself with them (the domains differ enough that this is minor).

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 is implied by 'latest or a date' and by calling out which fields are optional, so an agent can infer the normal call pattern. There is no explicit guidance on when to prefer this over another tool, what happens with an invalid date or unsupported symbol, or any prerequisite, so it stays at minimum-viable.

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 exist, so the description carries the full behavioral burden. It usefully discloses a cost of 1 credit, but says nothing about the return shape (holiday names, dates, locality scope), nor what happens when country or year are omitted even though both parameters are optional.

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?

One compact sentence with the core purpose front-loaded and the cost note trailing as a parenthetical. No wasted wording, though the credit note is slightly buried rather than integrated.

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 lookup with no output schema, the definition covers the essentials but leaves notable gaps: default behavior when both optional parameters are omitted and a hint at the returned fields. Adequate but not 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 description adds real value for `country` by giving ISO-code examples (GB, US, DE, FR) that the schema's bare 'string' does not. It adds nothing for `year`, whose accepted format (numeric 2024 vs. string) and default remain unclarified despite 100% nominal schema coverage.

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 the resource (public holidays) plus the two scoping inputs (country, year), which is enough for an agent to know exactly what it retrieves. Siblings (convert_time, fx_rates, time_now) are clearly unrelated, so no explicit differentiation is needed.

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 is only implied by the resource name; there is no explicit statement of when to call it versus another tool or of any prerequisites. Given the sibling set is disjoint (time conversion, FX rates, current time), the lack of exclusions costs little.

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 exist, so the description carries the full disclosure burden, and it does useful work: it states the response contents (offset and unix time) and a per-call cost of 1 credit, which is real behavioral context an agent would not otherwise have. It stops short of covering error behavior for an invalid timezone, which keeps it from a 5.

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?

One front-loaded sentence covers purpose and return values, with the cost note appended in parentheses. Nothing is redundant and nothing needs to be hunted for.

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 zero-required-parameter read tool with no output schema, the description compensating by naming the returned fields makes it essentially complete. The only gap is unstated behavior on an invalid IANA zone, which is minor at this complexity level.

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 schema already documents the single optional parameter as an IANA zone defaulting to Europe/London. The description only restates 'in a time zone' and adds no format or default detail beyond the schema, so baseline 3 applies.

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 names a specific resource (current time) and scope (in a time zone) and even enumerates the returned fields (offset, unix time), so the agent knows exactly what it gets. It does not explicitly distinguish itself from the sibling convert_time, but the 'current time' framing is clear enough on its own.

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 is implied rather than stated: an agent can infer 'use this to get the present time' and 'use convert_time to translate a given timestamp.' There is no explicit when-to-use, when-not, or named alternative, so guidance stops at inference.

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