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

Annotations already declare readOnlyHint and openWorldHint, yet the description adds real behavioral context: results are deduplicated and sorted by distance from the origin, the corridor is sampled along the polyline, and the Key must be configured first. It does not warn about sampling-induced coverage gaps, rate limits, or cost, which keeps it below a 5.

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?

Purpose is front-loaded, then parameters, then implementation, then the Key prerequisite — a sensible order. The '实现方式' sentence about /v3/direction/driving and /v3/place/around sampling is longer than strictly required for invocation, but it does build justified trust in result quality.

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 still states the return shape (a list of target POIs sorted by distance from the origin) and covers the three required and three optional parameters. It omits expectations around sparse results or how many sample points are used, which is a modest remaining gap for a 6-parameter tool.

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 already 100%, so the baseline is 3. The description nevertheless adds meaning beyond the schema: distance is defined as a corridor that extends distance meters to each side of the route centerline (with a worked example), and it clarifies that origin/destination accept either address text or 'lng,lat'.

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 first sentence gives a specific verb (搜索), resource (目标 POI) and scope (沿驾车路线), plus the return ordering. The route-corridor scope inherently separates it from the point-based search_nearby sibling, but the description never names that sibling, so the differentiation is implicit rather than explicit.

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 supplies concrete selection context (target keyword examples such as 加油站/服务区/充电站) and an explicit operational prerequisite — '需要先配置高德 Key，未配置时调用 set_amap_key 即可' — which routes the agent to a sibling when setup is missing. It never states when NOT to use it or when to prefer search_nearby, so it stops short of full when/when-not coverage.

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

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external-network behavior are covered. The description adds real value beyond them: the results come back as a list ordered from nearest to farthest, and the tool depends on an API key being configured first.

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?

Front-loads the purpose, then location formats, then keyword examples, then the key prerequisite. Every sentence is relevant and there is no filler, though the keyword enumeration is somewhat list-heavy.

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?

All five parameters are documented in the schema, the return ordering is described despite there being no output schema, and the key prerequisite is spelled out. An agent has everything needed to invoke this 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 the schema already documents city, limit, radius, keyword, and location with defaults and bounds. The description largely restates the location formats and keyword examples, adding only a concrete coordinate sample. Baseline 3 is appropriate when the schema carries the load.

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 resource: query nearby POIs of a given type around an input location, returned sorted by distance. It is clear and concrete, but it does not explicitly contrast itself with the sibling search_along_route, leaving that differentiation to the name alone.

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?

Provides a concrete prerequisite and routing instruction: an Amap Key must be configured, and if not, call set_amap_key first. That is genuinely useful context. It does not, however, say when to prefer this over search_along_route.

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

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

Goes well beyond the annotations: it discloses that a real call to the Amap API is made against a test address first, that the write to the local config file is gated on validation passing, and that no restart or client reconfiguration is needed. For a mutating, open-world tool this is exactly the side-effect and sequencing information an agent needs.

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?

Three sentences, front-loaded with the action, then validation/write behavior, then the practical consequence for the caller. Each sentence carries distinct information and nothing is repeated from the schema or annotations.

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 single-parameter, no-output-schema tool with annotations covering read-only and open-world status, the description is essentially complete. Minor omissions: what error surface appears if validation fails, and whether a re-run overwrites an existing configured key.

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?

Only one parameter, and the schema already documents it at 100% coverage ('高德开放平台的「Web服务」类型 Key'). The description reinforces the Web-service key type constraint but adds no new format, length, or syntax detail beyond the schema, so the 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?

States a specific verb-and-resource pair: 录入并校验高德地图「Web服务」类型的 Key. It also scopes the effect (all later queries use it automatically), which cleanly separates this config tool from the query-oriented siblings search_nearby and search_along_route.

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?

Clearly states the trigger condition — the user provides a Key and calling this tool completes authentication — and explicitly rules out the alternative approaches (editing client config, restarting). It does not name a sibling or fallback tool, but the alternatives it excludes are the relevant ones for a setup step.

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