get_registers

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

There are no annotations, so the description carries the behavioral disclosure burden. It clearly signals a read-only operation ('Returns... snapshot') and discloses the critical prerequisite of a stopped emulator. It does not explicitly state what happens if called while running, but the requirement implies calling it in that state would be invalid.

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 sentence with no filler. The core function is stated first, followed by the necessary usage prerequisite, making it efficient and easy to parse for an agent.

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?

For a parameterless read-only snapshot tool with an output schema already present, the description covers all necessary operational context: what it returns and the required emulator state. No additional information is needed to invoke it correctly.

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, and the schema confirms this with an empty properties object. There is no parameter-level information for the description to add, so the baseline for a no-parameter tool 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 clearly states a specific action: 'Returns the current C64 register snapshot.' This identifies both the resource (C64 registers) and the operation (retrieve a snapshot), and it is easily distinguished from sibling tools like set_registers, which writes rather than reads.

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 an explicit precondition ('Requires emulator to be stopped') and a concrete remedial action ('call execute(action="pause") first if running'). This tells the agent exactly when the tool is valid to call and how to get the emulator into that state.

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