open_folder

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

With no annotations provided, the description carries the full burden: it opens with 'Read-only', which clearly signals a non-mutating safe operation, and it discloses the return shape as a {nodes, edges, manifest} graph. It also explains that the result is a coarse L0 view, which is important behavioral context for how the tool should be used.

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 two focused sentences. It front-loads the most important safety and semantic information ('Read-only', 'L0 folder graph'), then gives usage context and return shape with no filler.

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?

Given there is no output schema, the description usefully names the return graph shape ({nodes, edges, manifest}). It also explains the folder->file->declarations hierarchy and how this tool fits the navigation workflow. It could go slightly deeper on what 'manifest' contains, but for an orientation tool, the coverage is strong.

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 description coverage is 100%, so the baseline applies. The description reinforces that 'root' is a path prefix and ties it to the graph orientation, but it does not add meaningful detail about the 'format' parameter beyond what the schema already provides.

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 operation (open a folder graph) with a clear resource and scope: an L0 folder graph rooted at a path prefix, with the structure folder -> file -> declarations. It also distinguishes itself from the sibling tools open_file and read_body, making its role unambiguous.

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?

It explicitly says this is the coarsest orientation move and should be used to see what lives under a directory before drilling in with open_file or read_body. This gives clear when-to-use guidance and names concrete alternatives, so an agent knows how to route among related tools.

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