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 fully covered and the description's burden is low. The description adds value by enumerating the analytical layers produced (nhân nghiệp, quả báo, thời điểm kích hoạt, remedies), which tells the agent the output is a deep multi-part reading rather than a summary. It does not say how long or structured the response is, nor that results depend on birth-time accuracy — a meaningful behavioral caveat for this kind of tool.

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 a single dense sentence with the core purpose front-loaded, and the four analytical layers are enumerated in a natural reading order from cause to timing to remedy. The parenthetical "(Remedies)" is slightly redundant, but there is no filler or repetition requiring removal.

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 read-only, idempotent tool with five fully documented parameters the input side is complete, and the description does characterize the output's conceptual content. However, with no output schema, the agent gets no sense of the response's shape, depth or size for what is clearly a long interpretive report, and there is no differentiation from the chart-building siblings that share the same inputs.

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 100% — every parameter including gender encoding (0/"nu", 1/"nam"), birth_time, hour_index and timeline_years is documented in the schema itself. The description mentions no parameters at all and adds no meaning beyond that, so the baseline 3 for a fully documented schema applies.

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 a specific deliverable: a multi-layer karma reading ("Luận giải Nghiệp Lực đa tầng") that combines Tử Vi and Bát Tự and decomposes into four outputs — past-life causes, this-life retribution, activation timing via đại vận/lưu niên, and Buddhist remedies. That is much more specific than a generic chart tool. It stops short of a 5 because it never names or contrasts itself with the obvious siblings (tuvi_chart_vn, bazi_chart, karma_diagnose), so an agent must infer the split.

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?

Usage is only implied: the phrase "kết hợp Tử Vi & Bát Tự" signals this is the combined-karma analysis rather than a plain chart, which hints at when to pick it over tuvi_chart_vn or bazi_chart. There is no explicit when-to-use statement, no when-not, and no mention of prerequisites such as needing an accurate birth time for the timing layer to be meaningful.

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