Workspace Roots

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

Beyond readOnlyHint=true and openWorldHint=false, the description discloses that read-only roots are segregated into readOnlyDirs and that writes, moves, and deletes under them are refused — a concrete consequence an agent would not otherwise know. It stops short of describing ordering, empty-list behavior, or error modes.

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?

Three short sentences, front-loaded with what is returned, then the read-only caveat, then the grant path. Each sentence carries distinct, actionable information with no repetition of 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 output schema, the description does the work of explaining that results are absolute paths and that read-only entries land in a separate readOnlyDirs collection. That is nearly sufficient, though the exact response shape (single list vs. two collections) remains slightly ambiguous.

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, so there is nothing for the description to disambiguate; the baseline of 4 applies. Nothing about the description misrepresents the parameter surface.

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 the directories this server can access') plus the return form ('as absolute paths'). This clearly separates it from the file-content siblings such as list, stat, and find_files, which operate on entries rather than access roots.

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?

Usage is implied: it says session-granted paths are included and that other tools can request access to paths outside these roots, which hints at calling this first to discover scope. However, it never states explicitly when to call it versus alternatives, nor any when-not condition.

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