Retune an indicator already on the chart. Identify it by the instanceId from chart_state, not by its study id — the same indicator can be on the chart more than once at different settings. Changes the chart you are building; call chart_link when you are done so the person can open it.
| Name | Required | Description | Default |
|---|---|---|---|
| params | Yes | ||
| instanceId | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations indicate this is not read-only and not destructive, aligning with the description stating it 'changes the chart you are building'. It adds a workflow requirement (call chart_link) and clarifies the identification nuance, providing useful behavioral context beyond the annotations.
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 sentences with no waste, front-loading the core purpose and then adding the identification and workflow notes. Efficient and well-structured.
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?
The description covers the essential steps: identify by instanceId, change settings, and link the chart. It lacks details on the params structure and error handling, but given the simplicity and the existence of sibling tools, it's reasonably complete for an agent to invoke 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 description explains that instanceId is from chart_state and that the same indicator can appear multiple times, which adds meaning beyond the schema. However, it doesn't elaborate on the structure of the 'params' object, which has 0% schema coverage, leaving the agent to infer what settings to pass.
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 'Retune' with a clear resource 'indicator already on the chart' and differentiates from siblings by emphasizing the instanceId identification rather than study id. This distinguishes it from chart_add_indicator, chart_remove_indicator, and chart_toggle_indicator.
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?
Provides context that instanceId comes from chart_state, implying the agent must fetch chart_state first, and mentions the workflow of calling chart_link after changes. It doesn't explicitly name alternative tools or state when not to use it, but the phrasing implies other tools for add/remove.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.