scenario

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses that scenarios are stored in a hidden '_mcp_scenarios' sheet, that 'apply' is destructive, and mentions potential user-visible side-effects when opening the workbook. This is excellent coverage of behavioral traits.

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 well-structured with labeled sections (Args, Returns, Notes) and a clear hierarchy. While it is more verbose than simpler tools, the length is justified by the complexity of the action-dependent parameters and the need to explain the nested cell_values structure. No sentence is wasted.

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?

This is a multi-action tool with variable parameters, and the description covers all necessary context: the action enum, per-action requirements, return types, and side-effects. Given the complexity and the presence of an output schema, the description provides complete guidance for an agent to select and invoke the tool 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 schema has 0% description coverage, but the tool description thoroughly explains every parameter, including the nested structure of cell_values with a concrete example. It also clarifies the conditional requirements for name and cell_values based on action, going far beyond what the bare schema provides.

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 opens with 'Manage saved scenarios (what-if value sets) persisted in a hidden sheet,' which clearly identifies the tool's function and scope. It distinguishes itself from sibling tools by focusing on scenario persistence and manipulation, not on direct cell operations or analysis.

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 explicitly breaks down the three actions (add, list, apply) with their required arguments, which serves as clear usage guidance. It does not explicitly mention alternatives or when not to use the tool, but the action-based structure implies appropriate use cases.

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