list_file_roots

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so safety is covered structurally. The description adds one genuinely non-structured piece of information: that each root is returned with permissions indicating read vs write access. It does not describe behavior when a root is absent, when permissions are unavailable, or whether the result varies by connection/auth state.

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 short sentences, zero filler, with the resource and its enumeration front-loaded and the practical payoff (permission discovery) second. Nothing repeats the tool name or the annotations.

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?

With no parameters and an output schema present, the description only needs to orient the agent, which it does by naming the root types and the permission payload. A small gap remains: it does not say whether this must be called before operations on a given root, nor whether roots can be restricted or missing for a given printer.

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 takes zero parameters (empty object schema, 100% coverage), so there is nothing for the description to disambiguate; the baseline for a no-parameter tool applies. The description correctly implies no arguments are needed by framing the call as a simple enumeration.

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 names a specific resource (the printer's file roots) and enumerates the concrete kinds returned (gcodes, config, logs, timelapse), so the agent knows this is a discovery call rather than a directory content listing. It stops short of explicitly contrasting itself with list_directory or list_gcode_files, so sibling differentiation is only implied.

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?

"Tells you where you may read and write" implies the call is a prerequisite step before file operations, which gives usable context. However, there is no explicit when-to-use statement, no exclusion (e.g. 'use list_directory to enumerate contents of a root'), and no note about prerequisites such as authentication or an active printer connection.

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