Mark a trace as completed to finalize an agent workflow and prevent any further steps from being added.
Mark a trace as completed. No further steps should be added after this call. Example: { "trace_id": "abc-123" }
| Name | Required | Description | Default |
|---|---|---|---|
| trace_id | Yes | ID of the trace to complete. Example: "abc-123-def-456" |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false and destructiveHint=false, so the agent knows this is a non-destructive mutation. The description adds the terminal-finality trait, but says nothing about idempotency or what happens if the trace is already ended or does not exist.
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?
Two short sentences plus an example, with the core action front-loaded. The example partially duplicates the schema example, which is slightly redundant but not wasteful.
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 one-parameter terminal-marker tool with no output schema, the description covers the essential action and the key sequencing rule. Error behavior and idempotency are the only notable omissions, which are minor at this complexity.
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% for the single trace_id parameter, so the schema already carries the semantics and the description's inline example duplicates the schema's own example. Baseline 3 applies when the schema does the heavy lifting.
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?
States a specific verb and object ('Mark a trace as completed'), which is unambiguous about the operation performed. It does not explicitly contrast itself with siblings like trace_start or trace_step, but the start/step/end naming family makes the role inferable.
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 ordering constraint 'No further steps should be added after this call' is genuine timing guidance, telling the agent this is terminal. However, it names no alternatives or conditions for when to leave a trace open instead, so usage is only implied rather than explicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.