list_files

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered and the bar is lower. The description adds only the fact that the target is the SD-card filesystem; it says nothing about whether results are recursive, sorted, truncated, or how many entries come back.

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?

One short, front-loaded sentence with no filler; the examples earn their place by documenting the path format. Nothing is redundant with the annotations or schema, though the single sentence leaves no room for routing guidance.

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 one-parameter read-only listing tool with no output schema, the description covers the essentials (what it lists, where, example paths). It is still incomplete on return shape — file names only vs metadata, recursion, ordering — which an agent would want before calling.

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 coverage is 0% for the single 'dir' parameter, so the description is the only source of meaning — and it does supply concrete example paths (0:/gcodes, 0:/macros, 0:/sys) that the schema lacks. Still, it does not clarify path conventions (trailing slash, relative vs absolute, other volume prefixes) or whether the default is applied when omitted.

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 and resource ('List files') plus the exact scope (the Duet SD card), which distinguishes it from machine-state siblings like get_status or get_sensors. It does not, however, distinguish itself from read_file, the other filesystem sibling, so an agent must infer the listing-vs-reading split on its own.

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 when-to-use statement, no prerequisites, and no named alternative (read_file is the obvious one for the same filesystem). The directory examples hint at typical usage but give no selection criteria between this tool and its siblings.

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