Hour Pillar

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows this is a safe read operation. The description adds the method (Five-Rats-Escape) and a timezone rule, which provides some additional context but does not significantly expand behavioral transparency beyond 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 concise with two sentences plus an example and group label. The first sentence clearly defines the method and purpose, the second provides a critical time rule. The example is a quick illustration. No extraneous text, but the structure could be slightly improved by placing the example after the parameter explanations.

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 annotations, no output schema, and 4 parameters with full schema coverage, the description covers the core method and a key timezone nuance. However, it does not describe the output format (e.g., stem and branch) or explain the role of latitude/longitude parameters. Slight gaps in completeness for a tool with no output schema.

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% with descriptions for all four parameters. The description does not add extra meaning to the parameters beyond the schema. The example request body provides a usage illustration, which is helpful but does not deepen parameter understanding. 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 states it computes the 'hour pillar' via the Five-Rats-Escape method, clearly specifying the verb ('compute') and resource ('hour pillar'). It distinguishes from sibling tools like bazi_month_pillar and bazi_year_pillar by focusing on the hour component, which is unique among the BaZi pillar 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 implies usage for hour pillar calculation but does not explicitly state when to use this tool versus alternatives like bazi_month_pillar. It includes a specific timezone note (Zi-hour starts at 23:00 CST) and an example request, which helps context, but lacks when-not or exclusion guidance.

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