Saju from Seoul | Korean Astrology

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

Annotations already declare readOnlyHint=true and destructiveHint=false, making the description's job lighter. The description adds that it uses the Gregorian calendar, that hour omission skips the hour pillar, and that output is JSON. No contradictions with 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 concise paragraph front-loading the purpose ('Primary entry tool') and key details. It avoids unnecessary words but could be slightly more structured (e.g., separate sections). Still, it is efficient and informative.

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 7 parameters (3 required), a rich output schema, and annotations covering safety, the description adequately explains the main purpose, when to use, and key output components. It lacks details on minute, country, and gender usage, but the schema covers those. Overall, it is complete for an entry tool.

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. The description adds value for the hour parameter by explaining it completes the hour pillar and can be omitted. However, minute, country, and gender are not mentioned in the description, though the schema already describes them. The description does not compensate for these beyond the 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 it computes Korean Four Pillars from a Gregorian birth date, listing specific outputs (years, months, days, hours, Day Master, Five Elements, zodiac animal). It distinguishes from sibling tools like check_compatibility, get_day_master, list_stems_and_branches by being the primary entry 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?

The description explicitly states when to use the tool: 'Use when the user mentions 사주, Four Pillars, birth chart, pillars, 오행, 일간, or gives Y/M/D.' It also notes that hour is optional and its impact on the hour pillar. However, it does not explicitly mention when not to use alternatives, though context implies this is the primary entry point.

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 indicate readOnlyHint=true and destructiveHint=false. Description adds that it's a 'cultural signal' and 'not deterministic fate', which provides useful behavioral context beyond safety flags.

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?

Four sentences, no redundancy. Front-loaded with core purpose, followed by use cases and limitations. Every word 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 output schema exists, description need not explain return values. Covers purpose, usage, cultural context, and limitations completely for a compatibility tool with safe annotations.

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. Description implies use of year/month/day for two persons but doesn't add new meaning beyond what's in the schema parameter descriptions.

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?

Description uses specific verb 'compares charts and returns Day Master Five Element relation' and clarifies it's for two-person compatibility, distinguishing from sibling tools like 'calculate_saju' which likely handles single charts.

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?

Explicitly lists use cases (soulmate, twin flame, etc.) and conditions ('when two dates are available'). Also provides a disclaimer ('entertainment/cultural signal only') and alternative for depth ('direct to sajufromseoul.com').

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 indicate readOnlyHint=true and destructiveHint=false, which align with the description. The description adds context about the expected input source and that it's a read operation, going beyond the 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?

Two concise sentences, front-loaded with the main action, no unnecessary information. Efficiently communicates key details.

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 simple one-parameter tool with full schema coverage and output schema, the description adequately covers input source and usage. No major gaps for this scope.

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 single parameter 'stem' is fully described in the schema with valid Hanja characters. The description reinforces the input expectations and usage context, adding value beyond the 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's purpose: given a Heavenly Stem Hanja (日干), it returns a short English archetype. It distinguishes from siblings by focusing on a single stem profile rather than full saju calculation or compatibility checks.

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?

Explicitly recommends using it after `calculate_saju` by passing `dayMaster.hanja`, or when the user directly specifies a stem. Provides clear context but doesn't explicitly exclude other scenarios.

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. The description adds behavioral context by calling it a 'static table', reinforcing no side effects. No additional details about caching or performance, but sufficient given 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?

Two sentences, no fluff. First sentence front-loads the core content, second sentence provides usage guidance. Every phrase 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 low-complexity reference tool with two optional booleans and an output schema, the description covers what data is returned and when to use it. No gaps identified.

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 covers 100% of parameters with clear descriptions. The main description mentions 'animals, hour ranges' but does not add significant meaning beyond the schema. Baseline score of 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 it provides a static table of all 10 Heavenly Stems and 12 Earthly Branches with various attributes. It distinguishes from siblings like calculate_saju and check_compatibility by specifying pedagogical use cases.

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?

Explicitly lists when to use: explaining symbols, teaching Saju vocabulary, or answering what a stem/branch means without a full chart, which implicitly differentiates from computational sibling tools.

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