path_exists

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

With no annotations, the description carries the full transparency burden. It adds a valuable detail about checking both overlay and real filesystem, but it does not disclose return behavior (e.g., boolean vs exception), side effects, or permissions. For a simple existence check, this is adequate but not exhaustive.

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, front-loaded sentence with no redundant wording. It communicates the core purpose and an important scoping detail efficiently, earning a top score.

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 one fully described parameter and no output schema. The description covers the operation's scope (sandbox, overlay+real fs) adequately. However, because no output schema exists, explicitly stating the return type (e.g., true/false) would make it fully complete.

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 schema already provides full coverage for the single parameter (sandboxPath). The description adds no additional parameter-level meaning beyond what the schema states, so the baseline of 3 is appropriate.

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 tool checks if a path exists in the sandbox, with a specific verb and resource. It mentions the overlay+real fs scope, providing useful context. However, it does not explicitly distinguish itself from sibling tools like realpath or bash_exec, so it's not a 5.

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?

The intended use is implied (when you need to verify path existence in the sandbox), but no explicit guidance is given about when to prefer this over alternatives. There are no exclusions or alternative tool references, so it falls short of clear usage direction.

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