Japan Business Calendar MCP

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

No annotations are provided, so the description carries the full behavioral burden. It never states whether weekends and Japanese public holidays are excluded, what date format is expected, whether negative values are supported (only implied by 'add/subtract'), or what the response contains. 'Japanese business days' is the only real behavioral signal.

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, front-loaded with the action and domain. The 'PRO.' prefix is trivial overhead but the rest is efficient with no 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?

A mutation-free but computation-heavy tool with no annotations, no output schema, and two of three parameters undocumented. The description should explain the holiday calendar semantics, date input format, and negative-day behavior, and it explains none of these.

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 only 33% (only access_token is documented in the schema). The description implies 'days' can be negative and 'start' is a date, but gives no format, range, or sign conventions, and never mentions the required access_token. It does not compensate for the low 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 a specific verb (add/subtract) and a specific resource (Japanese business days) applied to a date. It is clear on its own, though it never names or contrasts with siblings like next_holidays or due_date, so differentiation is left to inference.

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 when-to-use or when-not-to-use guidance and no pointer to alternatives such as due_date or year_planner. The 'PRO' prefix conveys nothing actionable about 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?

With no annotations, the description must carry the behavioral burden. It discloses the core additive rule and mentions calendar versus business days, but omits the default mode, allowed mode values, weekend/holiday handling, date parsing rules, and return format.

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 definition is a single front-loaded sentence with no filler, making the core formula immediately visible. The leading 'PRO.' is unexplained, but otherwise the structure is efficient.

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 low schema description coverage, the definition leaves important invocation details unspecified. An agent would have to guess exact mode values, default behavior, date format, and whether holidays are considered.

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 only 25%, so the description needs to compensate. It identifies the roles of start, days, and mode through 'start + N calendar or business days,' but does not specify date format, numeric constraints, or exact mode strings.

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 operation: computing an invoice due date by adding N days to a start date, with calendar or business-day modes. It is clear what the tool does, but it does not distinguish itself from the overlapping sibling tool business_days.

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 'Invoice due date' implies a use case, giving some context for when the tool applies. However, it provides no explicit when-to-use guidance, exclusions, or routing versus siblings such as business_days, next_holidays, or year_planner.

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 behavioral burden. It discloses that results are free, limited to the next 3 Japanese holidays, and include a business-day flag for today, but it omits timezone assumptions, holiday definition details, and return ordering.

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 compact sentence with the key scope and return information front-loaded. 'FREE.' is slightly promotional, but the overall definition is efficient and waste-free.

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-parameter, no-output-schema utility, the description gives enough to understand the return values: next 3 Japanese public holidays and a today-is-business-day boolean. The main unresolved gap is timezone/locale context for 'today' and holiday calculations.

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 is nothing for the description to clarify about parameter semantics. The empty schema is self-evident and the description does not need to compensate.

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 resource and scope: the next 3 Japanese public holidays plus whether today is a business day. It is clear what the tool returns, but it does not explicitly differentiate itself from siblings like business_days or year_planner.

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 only usage-adjacent signal is 'FREE'; there is no guidance on when to use this tool versus business_days, due_date, or year_planner. The agent must infer appropriate use from the tool purpose alone.

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 burden, yet it discloses almost nothing: no pagination, no return shape, no date-range scope, and only a vague 'PRO' hint about access tier. The auth implication is left to the schema's access_token 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?

It is short and technically front-loaded, but 'PRO.' is an unexplained fragment that consumes prime real estate without conveying usable meaning. Brevity here reflects under-specification more than 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?

For a tool with no annotations, no output schema, and a subscription gating implied by 'PRO', the description omits the return format, completeness guarantees, and any auth prerequisites. It is too thin to let an agent call it confidently.

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?

Only one parameter and schema description coverage is 100%, so the schema fully documents access_token. The description adds no additional meaning about the token or its behavior, which is acceptable given the schema does the work (baseline 3).

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 phrase 'Full holiday list' signals the resource returned and implicitly contrasts with next_holidays, but there is no verb and 'PRO' and 'from the dataset' are cryptic. An agent can guess it returns holidays but cannot confidently distinguish it from 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?

'PRO' hints at a subscription requirement but there is no explicit when-to-use, when-not-to-use, or routing to next_holidays/business_days. The agent must infer that this is the complete-list alternative to the narrower siblings.

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