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

Annotations already establish readOnly, idempotent, non-destructive, non-open-world behavior, so the description only needs to add rendering semantics. It does: drag/zoom and hover-for-numbers interactivity, plus an important fallback — non-rendering chats receive a clickable URL to pass to the user.

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?

Content is front-loaded with the core action, then the fallback behavior. The bilingual CN/EN pairing duplicates the same information, which is defensible for mixed-language agents but is not maximally economical.

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 no output schema, the description carries the burden of explaining the return path, and it does so: an in-chat interactive map or, failing that, a link to hand to the user. Combined with full schema coverage, an agent has enough to invoke and relay the result correctly.

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%, so all five parameters are already documented in the schema. The description only loosely gestures at the inputs ('一條資料(或「需要度」)', '換算'), adding little beyond the enum and per-description detail the schema already carries.

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?

States a specific verb and output artifact: 'Draw an indicator as an interactive choropleth map of neighbourhoods', plus the granularity options (里/鄉鎮). It notes the equivalence to ranking ('換算同「排名」'), but does not explicitly contrast with siblings like overlay_metrics or compare_groups, so an agent must infer the boundary.

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 implied by the rendering context ('在對話裡直接顯示') and by the ranking-equivalence note, which hints this is the spatial visualization counterpart to rank. There is no explicit when-to-use, when-not-to-use, or named alternative among the sibling tools.

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