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

With no annotations, the description carries the full burden and does well: it declares 'Read-only', explains the diagnostic purpose (isolating CLI vs. credentials vs. workspace as a failure cause), and enumerates the reported state. It stops short of describing the return shape or any error/timeout behavior, but the read-only and diagnostic traits are clearly disclosed.

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 what gets checked, then usage, then the negative routing rule. The long enumeration is justified by the breadth of the check, but the third clause ('It reports the state of the machine and nothing else') and the sibling examples add density that slightly dilutes the core message.

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?

No output schema and no annotations, so the description must supply everything - and it enumerates the reported checks, declares read-only, and routes usage correctly. An agent has what it needs to select and invoke it; only the exact return format remains implicit.

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?

One optional parameter with 100% schema description coverage, so the schema already fully documents the workspace path and its CPS_WORKSPACE/current-directory default. The description only alludes to the workspace ('the agent workspace it found') without adding format or resolution semantics 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 (check) and resource (machine readiness), then enumerates exactly what is inspected: pac CLI/.NET, active auth profile, token-bearing cloud resources, env vars, write policy, and the discovered workspace. It explicitly draws the boundary against siblings ('reports the state of the machine and nothing else'), so an agent can distinguish it from cs_status, cs_guide, or cs_create_agent without opening schemas.

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?

Gives explicit when-to-use ('once at the start of a session, and again when a tool fails') and when-not ('when the user asked for something specific... call the tool for that thing instead'), naming cs_create_agent and cs_guide as alternatives. Nothing is left to inference.

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