Market Intel MCP

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

With no annotations, the description must carry behavioral disclosure on its own. It does state the rate source (ECB reference rate) and the return payload (rate, converted result, rate date), which is good. But it omits potential nuances such as ECB rate lag or business-day staleness, and does not explicitly confirm the operation is read-only.

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 leads with the action and resource, then summarizes the output. Every word carries information; there is no repetition of the tool name or schema descriptions.

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, and the description covers the core operation and return fields, which partially compensates for the missing output schema. However, it leaves out edge cases like unsupported currency codes, rate availability timing, or how 'latest' relates to ECB publication dates. These gaps are notable when no annotations or output schema exist.

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 all three parameters (amount, from, to) are already documented in the input schema. The description adds no parameter-level meaning beyond the schema, so the 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?

The description uses a specific verb ('Convert'), identifies the exact resource (amount between currencies), and names the data source ('latest ECB reference rate'). This clearly differentiates it from siblings like fx_historical and fx_timeseries, which serve different time-range purposes.

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 verb and resource: convert an amount at the current or latest rate. However, it does not explicitly tell the agent when to choose this over fx_historical, fx_rates, or fx_timeseries, and provides no 'when not to use' 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, the description carries the behavioral burden. It clearly signals a read-only listing operation and specifies what will be returned: currencies and their full names. It does not detail the exact return shape or ordering, but for a zero-parameter enumeration this is a minor gap.

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 ('List') and contains no filler. Every phrase contributes meaning: the domain (exchange-rate lookups) and the output detail (full names).

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, zero-parameter tool with no output schema, the description adequately states scope and output content. It could explicitly connect to siblings or describe the return format, but the sibling names are self-explanatory and the missing detail is minor for this kind of metadata endpoint.

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 tool has zero parameters, so there are no parameter semantics for the description to clarify. The empty input schema is fully covered, and the baseline of 4 applies because no parameter explanation is needed.

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 ('List'), a clear resource ('currencies supported for exchange-rate lookups'), and the expected content ('with their full names'). This clearly distinguishes it from the sibling conversion/rate tools because it enumerates supported currencies rather than performing exchange-rate operations.

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 implies the use case—call this when you need the set of supported currencies for exchange-rate lookups—but the description does not explicitly say when to use this tool versus alternatives like fx_rates or fx_convert. No exclusions or sibling routing 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, the description bears full behavioral disclosure responsibility. It clearly discloses the ECB source and the important fallback behavior for weekends/holidays, which is exactly the kind of context an agent needs. For a read-only lookup, this is sufficient.

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 with no filler. The core action comes first, followed by the single most valuable behavioral caveat about business days. Efficient and well-structured.

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 historical lookup with fully documented parameters and no output schema, the description provides the essential context: the data source and the prior-business-day fallback. It does not describe the response format, but that gap is minor for this tool's simplicity.

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 each parameter (base, date, symbols) already has a definition. The tool description adds no parameter-specific meaning beyond the schema; it merely restates the date format, so the baseline score of 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 states a specific verb ('get'), resource ('foreign-exchange rates'), and scope ('specific past date'), making the tool's function clear. It does not explicitly name sibling tools, but 'specific past date' implicitly distinguishes it from current-rate or time-series tools.

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 explicit guidance on when to use this tool versus alternatives like fx_rates or fx_timeseries. The historical-date framing implies usage, but no exclusions or sibling tool mentions 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?

No annotations are provided, so the description carries the full burden. It does add meaningful behavioral context beyond the schema by disclosing the data source (European Central Bank reference rates), which implies provenance and periodic refresh. However, it does not disclose what happens with unknown currency codes, whether all rates are returned when symbols is omitted, or the response structure, which are gaps for a tool with zero annotation coverage.

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 filler: the verb, resource, default, and optional filtering are front-loaded, and the source attribution earns its place because it communicates data provenance. Nothing could be removed without losing information.

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 tool with two optional parameters fully documented in the schema and no annotations, the description covers all invocation essentials: what is fetched, the base default, optional filtering, and data source. The only notable gap is the unstated return shape, since no output schema exists, but the tool is simple enough that an agent can proceed without it.

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 even with no parameter info in the description. The description merely reinforces what the schema already states (default USD base, optional comma-separated targets); it adds no new semantic detail such as accepted value formats beyond the schema's own examples.

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 verb ('Get'), a clear resource ('latest foreign-exchange rates'), and a scope ('for a base currency, optionally limited to specific target currencies'). The word 'latest' distinguishes it from the sibling tools fx_historical and fx_timeseries, while 'rates' separates it from fx_convert and fx_currencies, so an agent can pick it without opening schemas.

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 — this is the current-rates tool with an ECB source and optional symbol filtering — so usage is implied. However, it never explicitly names alternatives or states when NOT to use it (e.g., 'for past dates use fx_historical'), leaving the agent to infer the boundary against siblings.

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 discloses the approximate one-year range limit and implies a series of exchange rates, but it does not cover other behavioral details such as output structure, rate limits, or handling of invalid date ranges. 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 that communicates the tool's purpose, its primary use case, the date range limit, and the input requirements without any filler or redundancy. Every part 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 read-only tool with fully documented parameters, the description covers the core operational details: purpose, date range, input formats, and target currencies. There is no output schema, so the response shape is not specified, but the phrase 'time series' gives a reasonable expectation of the return concept.

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 reinforces that start and end are YYYY-MM-DD and that one or more target currencies are needed, but it does not add meaning beyond what the input schema already documents, such as the comma-separated format or the default base currency.

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: retrieving a time series of exchange rates for a base currency over a date range. It also adds the use case of trend analysis, which helps distinguish it from a simple conversion or currency-list tool, though it does not explicitly contrast with the similarly named fx_historical or fx_rates 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?

The description gives clear context for when to use the tool: for trend analysis over a date range of roughly up to one year. It does not explicitly mention alternatives or exclusions, but the stated use case is sufficient for an agent to select it appropriately in most situations.

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