Add a field-backed reference line to a configured worksheet pane.
Add a field-backed reference line to a configured worksheet pane.
| Name | Required | Description | Default |
|---|---|---|---|
| label | No | ||
| scope | No | per-pane | |
| formula | No | average | |
| tooltip | No | Average = <Value> | |
| axis_field | Yes | ||
| label_type | No | value | |
| pane_index | No | ||
| probability | No | 95 | |
| value_field | Yes | ||
| worksheet_name | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.28.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden, and it delivers little: no note on permissions, whether the line can be modified/removed, what happens to existing lines, or the side effects of a write ('add') operation. The phrase 'configured worksheet pane' faintly implies a prerequisite but is never made explicit.
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?
A single, front-loaded sentence with no wasted words. It is efficient, though the brevity contributes to the under-specification rather than reflecting disciplined conciseness.
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 10-parameter mutation tool with no annotations and no parameter documentation, one sentence is far too thin; only the existence of an output schema relieves the description of explaining return values. An agent lacks enough information to call this correctly against its siblings.
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?
With 10 parameters and 0% schema description coverage, the schema documents nothing. The description only hints at field dimensions via 'field-backed', giving no meaning for label, scope, formula, tooltip, label_type, pane_index, or probability — a substantial gap the description fails to close.
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?
Clear verb+resource: it adds a 'field-backed reference line' to a 'configured worksheet pane'. That is more specific than a bare restatement, but it never distinguishes this from the near-identical siblings add_reference_band and add_percentage_band, which an agent must choose between.
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?
There is no statement of when to use this versus alternatives, no prerequisites beyond the implicit 'configured pane', and no conditions for choosing a reference line over a band or percentage band despite their obvious overlap.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.