get_boot_critical_chain

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

With no annotations provided, the description carries the burden of safety and behavior. It states 'Read-only' and discloses failure conditions ('fatal only if systemd-analyze is missing or fails'). It also explains the optional unit parameter's effect, adding meaningful context beyond the schema.

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?

The description is three sentences with no fluff, front-loading the core function and then adding parameter and safety notes. Every sentence earns its place, making it efficiently scannable.

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 tool is simple (one optional param) and has an output schema, so return values are covered. The description covers purpose, usage, parameter behavior, and error conditions, making it complete for this read-only diagnostic 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?

The schema already has 100% coverage for the single parameter, including a description. The tool description adds a brief restatement ('Optional unit param starts the chain from a specific unit') but no new semantic detail, so the baseline score 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?

The description states a specific verb ('Returns') and resource ('time-critical boot chain from systemd-analyze critical-chain'), and clarifies it's a dependency tree with active-time and duration. This clearly differentiates it from siblings like get_boot_blame or get_boot_time.

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 gives a clear use case: 'Use to find what delays the boot target.' It implies when to use this tool, though it doesn't explicitly exclude alternatives. This is sufficient context for the agent to decide.

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