host_runtime_detect

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

With no annotations, the description fully carries the burden. It explicitly states the tool is READ-ONLY, never reads file contents, never mutates config, and does not auto-apply anything. This provides complete behavioral transparency.

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: tool purpose, behavioral constraints, output summary. Every sentence adds essential information, no redundancy or fluff. Front-loaded with the key action.

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?

Despite no output schema, the description details the return value (guess, candidate hosts with evidence, CLI fallback) and the authoritative flag. The tool's complexity is low, and the description covers all necessary aspects for an agent to invoke and interpret results.

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 100% with a description for runId. The description adds the context that runId is 'only used to journal', clarifying its optional, non-functional purpose beyond what the schema states. This adds meaningful value.

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 clearly states the tool performs an advisory guess of the host runtime based on MCP config files, with a specific verb ('detect') and resource ('host runtime'). It is distinct from all listed sibling tools, which cover recording, benchmarking, execution, etc.

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 implies the tool is used for detecting the host runtime and notes that SUPER_LOOP_HOST is authoritative, but does not explicitly state when to use or avoid this tool compared to alternatives. No direct alternatives exist among siblings, so guidance is adequate but not explicit.

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