Sets a register value in an active debug session to alter CPU state and control execution flow. Provide the session ID, register name, and hex value to apply the change.
Set a register value in the debugged process.
| Name | Required | Description | Default |
|---|---|---|---|
| value | Yes | Value to set (hex string, e.g. "0x41414141") | |
| session_id | Yes | Debug session ID | |
| register_name | Yes | Register name (e.g. "rax", "eip", "rflags") |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It fails to mention that setting a register mutates the debuggee's state, can affect execution flow, or requires an active debug session. The description is not misleading, but it is under-disclosing for a state-changing debugger operation.
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, succinct sentence with no redundant content. It is appropriately front-loaded for a simple setter tool, though it sacrifices some useful behavioral detail for brevity.
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 mutation tool with no annotations and no output schema, the description is too sparse. It does not mention return values, failure modes, or side effects on the debugged process, and it assumes the user already knows to provide an existing debug session ID.
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 100%, and the parameter descriptions already provide examples and types for value, register_name, and session_id. The tool description adds no additional parameter-level meaning, so the baseline of 3 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 uses a clear verb+resource pair: 'Set a register value' in the 'debugged process'. It is unambiguous about what the tool does, but it does not differentiate it from sibling tools like esil_set_register or rzil_set_register, which also set register values in emulator contexts.
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 phrase 'in the debugged process' and the required session_id imply this is for live debug sessions, which is useful context. However, the description gives no explicit guidance about when to use this over alternatives such as esil_set_register, rzil_set_register, or debug_write_memory, and no exclusions are stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.