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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the credit cost (5 credits, Tier ½), which is genuinely useful behavioral context not present in the annotations, but it says nothing about what the calculation consumes or returns.

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 text is short and front-loaded, but it is an under-specified keyword fragment rather than a structured, information-dense sentence. Brevity here reflects omission of required context rather than disciplined conciseness.

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?

An output schema exists, so return values need not be explained, and annotations cover safety. But for a 6-parameter chart-calculation tool the description omits the essential framing — that it derives the Travel palace from a birth date/time within Zi Wei Dou Shu — leaving the agent to infer the tool's core contract from the name alone.

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 67%, and the required `date` and optional `time` parameters carry no schema description at all. The description provides zero parameter information (no date/time format, no mention that birth data drives the palace calculation), so it fails to compensate for the uncovered parameters.

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 the domain ('Travel, relocation, foreign opportunities') and the group tag identifies the Zi Wei Dou Shu system, so an agent can infer this returns the Travel palace's themes. However, it is a bare keyword list with no verb or resource statement — it never says it computes/returns the Travel palace for a given chart, leaving the actual action implied.

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 guidance on when to use this tool versus alternatives such as astroway_ziwei_twelve_palaces (all palaces) or the other palace-specific siblings, nor any prerequisites (e.g., that a birth date/time is required). The only contextual lines are metadata (group and credit cost), which do not help tool selection.

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