create_machine

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

With no annotations, the description carries the full responsibility for behavioral disclosure. It clearly states that the disc is mounted read-only, autobooted with SHIFT+BREAK, and that the model determines disc-image format compatibility. While it doesn't mention resource cleanup or side effects, the provided details are substantive and go well beyond a generic 'create' description.

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 four sentences, each serving a distinct purpose: main action, session_id importance, parameter behavior, and disc format compatibility. It is front-loaded with the primary purpose and contains no filler or redundant information.

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?

Given the tool's moderate complexity (2 params, output schema present), the description covers all crucial aspects: return value, parameter selection, mount behavior, and alternative tool usage. It also provides enough context to distinguish from siblings and for an agent to invoke it correctly in a multi-tool workflow.

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 only provides bare property names and defaults with no descriptions. The description richly explains both parameters: `model` enumerates accepted values with model names (b, master, mos35, compact), and `disc` is described as an optional path with mounting, read-only, and format implications. This fully compensates for the 0% schema description coverage.

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 opens with 'Boot a BBC Micro session,' which is a specific verb+resource statement that clearly distinguishes this tool from siblings like load_disc and boot_disc. It also states the return value (session_id) and its role as a prerequisite for subsequent tools, making its purpose unambiguous.

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 explicitly directs users to call `load_disc` directly for writeable or host-mutating mounts, contrasting with this tool's read-only mounting behavior. It also implies this should be used first by stating the returned session_id is required by every subsequent tool. This provides clear when-to-use and when-not-to-use guidance.

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