list_configured_files

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

No annotations are present, so the description carries full burden. It discloses the data source (XLSX_MCP_FILES env var), startup behavior, and that no filesystem search is needed. It stops short of explicitly stating the tool is read-only, but 'List' makes this obvious enough.

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 crisp sentences with the verb and core purpose front-loaded. Every clause earns its place—no wasted words, yet it conveys usage context and cross-tool integration.

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 tool is simple with no parameters and an output schema exists, so the description only needs to cover purpose and usage context. It fully explains when to call it and how its output feeds into other tools, making it complete for the agent.

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 tool has zero parameters and schema coverage is 100%, so the baseline for this dimension is 4. The description adds useful context by explaining how the returned file names integrate with other tools' `path` parameter, but since there are no parameters to describe, it cannot go higher.

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 'List files preloaded at server startup' with a specific verb and resource, and distinguishes this tool from all sibling tools (which operate on sheets/cells, not file inventory).

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?

Explicitly instructs 'Call this first if unsure which files are available' and explains how the result relates to every other tool's `path` argument, including the optional omission behavior. Provides clear when-to-use guidance with no ambiguity.

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