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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety. The description adds useful behavioral detail: it skips local weekends (with a specific example for Saudi Arabia) and public holidays, and supports negative add values. This goes beyond the annotation profile, but it does not clarify how holidays are sourced or what happens if both add and end are provided, which is a minor gap but acceptable given the safety covered by annotations.

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 front-loads the action and the two usage modes, then adds the relevant constraints (weekend and holidays). Every clause earns its place—no filler, examples are concrete, and the alternation between add and end is immediately clear. It is an efficient and well-structured 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?

Given the tool's moderate complexity (5 parameters, no nested objects) and the availability of an output schema, the description is reasonably complete. It explains the primary modes and key behavior (weekend/holiday skipping) but does not explicitly address edge cases like simultaneous add and end, parameter limits (though these are in the schema), or the exact return value format (which the output schema covers). Overall, an agent can likely call it correctly without further clarification.

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 80%, and the schema already documents start, end, where, and weekend. The description adds semantic value by explaining the two computation modes (add vs. count to end), giving concrete examples for the add parameter (positive and negative), and mentioning the weekend behavior. It does not reintroduce all parameters but enriches the core ones, which is sufficient for an agent to understand their roles without reading the full 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 states a specific verb ('Adds' or 'counts') applied to a clear resource (business days on a date), with concrete examples (add: 10 or -5) and the key behavior of skipping local weekends and public holidays. It is distinct from sibling tools like date_info (date facts) and holidays (holiday lists), so an agent can easily recognize what this tool does without opening its schema.

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 when to use the tool (whenever business-day arithmetic is needed) and gives two modes, but it does not explicitly mention alternatives or conditions for choosing this tool over siblings. For example, it does not state 'use holidays to retrieve holiday lists' or 'use date_info for calendar details.' The guidance is inherent but not explicit, leaving some ambiguity about boundary cases (e.g., both add and end 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?

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so no contradiction exists. The description adds meaningful behavioral nuance beyond annotations: 'today' is interpreted as UTC, and month addition uses month-end clamping. These details matter for correct invocation and are not present in the structured fields.

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 dense sentence that front-loads the core outputs and then adds optional operations. Every clause carries distinct information, with no filler or redundancy. It is compact yet sufficiently detailed.

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 rich input schema, output schema, and safety annotations, the description covers all functional behaviors an agent needs to invoke the tool correctly. It addresses the special 'today' value, the arithmetic semantics, and the days-until calculation. There are no significant gaps for this level of 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 the baseline is 3, but the description adds semantic value by explaining behaviorally what the parameters do: '+1 month' with month-end clamping and 'days until another date'. This goes beyond merely repeating parameter names and gives the agent useful interpretation context.

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 set of outputs (weekday, ISO week, day of year, leap year) and optional operations (date addition and days-until), which clearly distinguishes it from sibling tools like world_time or business_days. The title 'Facts and arithmetic for a date' reinforces the exact resource and operation. Nothing is vague or tautological.

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 when the tool is useful by enumerating its date facts and arithmetic capabilities, but it never explicitly says when to choose this over sibling tools such as business_days, holidays, or world_time. There are no exclusions or alternative routing hints, so an agent must infer usage from the feature list.

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?

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds valuable behavioral context: the scope (207 countries), the estimation of Islamic-calendar dates, and the inclusion of 'next holidays' in output. This goes beyond annotations and helps set expectations.

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 captures the core purpose, scope, and a key caveat. Every phrase adds value: the two usage modes, geographic scope, country count, and estimation note. No filler or redundancy.

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 complexity (4 params, output schema present, annotations covering safety), the description is fairly complete. It explains the main behaviors and limitations. Minor gaps like the exact output structure or pagination are not critical because an output schema exists. Slightly more could be said about what 'next holidays' means, but it is adequate.

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 high (75%+), so parameters are already documented. The description reinforces the meaning of 'where' (country/state/city) and the two usage modes (year or date), but does not add new parameter-specific semantics beyond what the schema provides. 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 clearly states the tool's function: retrieving holidays for a country/state/city for a year, or checking if a date is a working day. It specifies the resource (holidays) and the verb (get/check), and distinguishes from siblings like business_days or date_info by focusing on holiday data specifically.

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 contexts (yearly holidays, working-day check) but does not explicitly name alternative tools or conditions for when to use this tool versus siblings. It lacks explicit 'when-not-to-use' guidance, leaving the agent to infer from the tool's name and scope.

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?

Annotations only state readOnly and idempotent hints. The description adds rich behavioral detail: windows inside everyone's working hours (with default 09:00-17:00 unless given), up to 14 days, skipping weekends and holidays, and fallback to the closest time. This goes well beyond the annotations and informs the agent of the algorithm's edge cases.

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 primary use case immediately. Every phrase adds value: scope, working hours logic, day range, weekend/holiday skipping, and fallback. No redundancy.

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 an output schema present, the return format is covered. The description explains the core algorithm and parameter semantics sufficiently for correct invocation. Minor gaps like explicit timezone handling are implied by the tool's purpose but not stated; still, the combination of description, schema, and annotations is nearly 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 descriptions cover 50% (date and people formats). The description adds meaning for the people parameter (working hours can be specified) and the days parameter (up to 14 days), but doesn't clarify minutes or default behaviors beyond what the schema already provides. It partially compensates for the missing schema descriptions but not fully.

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 purpose explicitly: 'Use for any meeting across time zones' and describes the resource (meeting slots) with specific behavior (windows inside working hours, up to 14 days). It clearly differentiates from sibling tools like business_days, date_info, holidays, and world_time by focusing on scheduling rather than date/time facts.

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 when-to-use guidance: 'Use for any meeting across time zones.' It implies this is the go-to for scheduling across time zones, but doesn't explicitly mention when not to use it or reference alternatives. However, the scope is clear enough for an agent to route appropriately.

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?

Annotations already establish that the tool is read-only, idempotent, and non-destructive. The description adds valuable behavioral context beyond those hints: it flags times that DST skips or repeatsstitution and reports each place's offset and next clock change. This is especially useful for handling ambiguous local times.

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 three compact sentences that front-load the core behavior, then add examples, DST caveats, and output details without repetition. Every sentence earns its place and there is no unnecessary duplication of schema 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?

Given the presence of an output schema and robust annotations, the description covers the essential operational details: input formats, place identifier styles, DST ambiguity handling, and key returned fields. The only minor gap is explicit tool-selection guidance relative to its siblings, which is largely a usage-guideline concern.

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 documents `from` and `time` defaults but leaves `places` semantically bare. The description compensates by enumerating accepted place forms (city, country, zone, PST, UTC+4) and giving concrete time-string examples such as '2026-03-08 02:30' and '9am', turning bare parameter names into usable input guidance.

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: show the current time in up to 20 places or convert a local time across those places and display offsets and next clock changes. It is easily distinguishable from sibling tools like date_info, holidays, and meeting_slots, though it does not explicitly name an 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?

The intended use is implied clearly: time lookup or time-zone conversion across multiple places. However, the description never explicitly says when to prefer this tool over the sibling date/holiday/scheduling tools or when not to use it.

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