mame_set_reg

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

With no annotations supplied, the description carries the full burden of behavioral disclosure. It only states the action without explaining side effects, reversibility, required emulator state, or error behaviors—critical omissions for a mutation 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?

The description is a single, terse sentence with no wasted words, but it is under-specified. It reads more like a label than a helpful tool description, lacking structure and necessary usage context that would earn its place.

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?

In the absence of annotations and an output schema, the description is drastically incomplete. It does not mention return values, prerequisite emulator states, or how different CPU devices are addressed, leaving the agent with insufficient information for reliable invocation.

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 description coverage is 0%, and the description adds no parameter context. While 'reg' and 'value' are self-explanatory names, the 'device' parameter's format/default is undocumented, and the description fails to compensate for the schema's lack of field descriptions.

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 action ('Set') and the target resource ('one CPU register'), distinguishing it from sibling tools like mame_get_regs (read) and mame_write_memory (memory). However, it omits any mention of the device parameter or scope, falling short of full clarity.

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?

No guidance is provided on when to use this tool versus alternatives. There is no mention of prerequisites such as a paused emulator, nor any exclusionary context that would help the agent decide between this and related manipulation tools.

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