get_boot_time

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

No annotations are provided, so the description must carry the behavioral burden, and it does: it declares the tool is read-only and states the only fatal condition (systemd-analyze missing or failing). It does not discuss latency, privilege requirements, or whether output is cached, which keeps it short of a 5 for a no-annotation 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 sentences, zero filler, and the routing information is front-loaded right after the core purpose. The failure-mode note is compressed into a single clause rather than expanded into its own paragraph.

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?

An output schema exists so return values need not be explained, yet the description still lists the phases, which is enough for an agent to interpret results. With no parameters, no annotations, and a defined output schema, nothing needed for a correct call is missing.

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 tool takes zero parameters, so the schema-dimension baseline of 4 applies and there is nothing for the description to compensate for. The description adds the semantic context that the returned data are phase durations, which slightly aids interpretation without requiring parameter explanation.

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 ('Returns the phase-level boot breakdown from systemd-analyze time') and enumerates the exact fields returned (firmware, loader, kernel, initrd, userspace, total, target). It also names the two sibling tools it is not, so an agent can distinguish it from get_boot_blame and get_boot_critical_chain immediately.

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 an explicit use case ('Use to see which boot phase dominates') and routes to the alternatives with their respective jobs: get_boot_blame ranks slow units, get_boot_critical_chain traces the dependency path. The when-to-use and when-to-use-something-else conditions are both spelled out.

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