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

With no annotations, the definition must carry the full behavioral burden. It implies a read-only lookup (查詢) and discloses that the response covers cause and collision-type distributions, but says nothing about error behavior for invalid keys, empty results, or response shape details.

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?

One compact sentence front-loads the action and return content, then appends the parameter-provenance hint. Nothing is redundant and the semicolon cleanly separates purpose from input sourcing.

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 two-parameter read-only lookup, a reader can act on it correctly: the tool's purpose, its inputs, and where those inputs come from are all covered. Because there is no output schema, extra detail on the returned distribution structure would have helped, which keeps it short of a 5.

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?

Both parameters have full schema descriptions, so the schema already explains kind as an enum of intersection/road and hotspotKeyid as a code from get_cbi_hotspots. The description repeats the same provenance hint without adding format or constraint detail beyond the schema, so baseline 3 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 gives a specific verb (查詢) plus resource (單一肇事熱點) and states what is returned (肇因與碰撞類型分布), which separates it from the list-style sibling get_cbi_hotspots. It never explicitly contrasts itself with the sibling, but the word 單一 and the prerequisite reference make the difference reasonably clear.

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?

It clearly says where to get the inputs — hotspotKeyid and kind come from the results of get_cbi_hotspots — which is a concrete prerequisite chain an agent can follow. It does not state when not to use this tool or what to do when get_cbi_hotspots returns no match.

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