agent_scan

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

With no annotations provided, the description carries the full burden and does so thoroughly: it discloses the registry write, detection methods for bin vs endpoint types, the specific env vars checked for qwen, the return content, and the downstream rejection behavior. This is strong transparency for a side-effecting 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?

Three information-dense sentences with no filler: the first establishes purpose, scope, and side effect; the second covers detection logic and return values; the third explains downstream impact. Every sentence earns its place and the material points are front-loaded.

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?

The description is complete enough for an agent to select and invoke the tool correctly: it covers what gets written to the registry, how availability is computed, what is returned, and what happens when availability is false. Given the simple optional parameter and absence of an output schema, no critical operational gap remains.

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?

The single optional refresh parameter is already fully described in the input schema, including that rescans happen by default and the parameter exists only for semantic clarity. The tool-level description adds no parameter detail beyond the schema, so the high-coverage baseline of 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 action ('识别本地已安装的 worker CLI'), names the exact worker CLIs (claude/codex/qwen/opencode/dsh), and explains the registration side effect (AGENTS[name].available). It also declares the return payload (available + 缺失引导), which clearly distinguishes it from dispatch tools like run_claude and agent_invoke.

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?

The description creates a clear usage context by stating that workers with available=false are rejected by run_*/agent_invoke, implying agent_scan should be used as a preflight check before dispatch. It does not explicitly contrast with sibling listing/evaluation tools like agent_list or agent_eval, so it stops short of full when-not/exclusion guidance.

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