Excel MCP Server

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

Annotations provide readOnlyHint=false, destructiveHint=true, openWorldHint=true, and idempotentHint=false, indicating it's a destructive, non-idempotent write operation. The description adds minimal behavioral context beyond this, noting it applies 'style information' but doesn't elaborate on effects (e.g., overwrites existing styles, requires file access). It doesn't contradict annotations, so baseline is met with slight value addition.

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, clear sentence with no wasted words. It's front-loaded with the core action ('Format cells') and efficiently conveys the tool's purpose. Every part of the sentence earns its place, making it highly concise 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?

Given the tool's complexity (4 parameters, nested styles object, destructive operation) and rich schema (100% coverage) with annotations, the description is minimally adequate. It states the purpose but lacks details on usage, output (no output schema), or advanced behavioral traits. For a formatting tool with significant parameters, more context would improve completeness, but annotations and schema provide substantial coverage.

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%, with detailed parameter descriptions in the input schema. The description mentions 'style information' which aligns with the 'styles' parameter but doesn't add meaning beyond what the schema provides (e.g., explaining style object structure or usage). With high schema coverage, the baseline score of 3 is appropriate as the description doesn't compensate with extra insights.

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 clearly states the action ('Format cells') and resource ('in the Excel sheet') with the purpose ('with style information'). It distinguishes from siblings like excel_read_sheet (reading) and excel_write_to_sheet (writing data), but doesn't explicitly differentiate from excel_create_table (which might involve formatting). The purpose is specific but could be more precise about what formatting entails.

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?

No guidance is provided on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., file must exist), when not to use it (e.g., for data entry vs. formatting), or compare to siblings like excel_create_table for structured formatting. The description lacks context for tool selection.

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