open_containing_folder

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

With no annotations present, the description carries the full burden and does so: it discloses the visible side effect on the user's screen, that no file is highlighted/selected, that contents are never returned to the model, that the result is only a short text confirmation, and that headless machines yield a note instead. It also states safety boundaries — paths escaping the root are rejected and nothing is modified.

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?

Front-loaded with the action and the three path cases, then usage rules, then behavioral caveats — a sensible ordering with no filler. It is somewhat longer than needed because the usage restriction is repeated in the schema and again in the paragraph, but every sentence still carries real information.

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 single-optional-parameter side-effecting tool with no annotations and no output schema, the description covers everything an agent needs: invocation conditions, path resolution, failure modes (missing paths, root escape, no file manager), and what the result looks like.

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 already 100%, so the baseline is 3; the description adds genuine meaning on top by defining the empty-string case, the parent-folder resolution rule, and that absolute paths are accepted only when they remain inside MEMDRIVE_ROOT. It does not add format/syntax detail beyond the schema examples, so it stops short of a 5.

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?

Opens with a specific verb and resource ("Open the folder containing a file or directory") and immediately disambiguates the three input cases: a file opens its parent, a folder opens itself, an empty path opens the library root. It is clearly distinguishable from list_directory, which is named as the way to actually see contents.

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 states the when ("USE ONLY WHEN THE USER EXPLICITLY ASKS TO OPEN THE FOLDER"), gives example phrasings including a non-English one, names explicit exclusions (never after read_file/save_file or any other tool call), and routes to the alternative (list_directory) for the different need of inspecting contents.

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