willys_open_file

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

With no annotations, the description carries the full burden. It discloses that the tool opens a file in the user's editor, does not read content, and is intended for .env setup. This gives the agent a clear safety profile, though it omits error behavior or return values. For a simple action, this is adequate transparency.

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 concise and front-loaded with the core action, followed by usage context, rationale, and a limitation. Every sentence adds distinct value with no filler or repetition.

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-parameter tool with no output schema, the description covers what, when, why, and what it does not do. It lacks explicit return value or error handling details, but the use case is well-anchored to the setup flow, making it nearly complete. Minor gap prevents a 5.

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 fully describes the path parameter, including its use for .env and its source from willys_setup. The description adds no new parameter semantics beyond reconfirming the path source. With 100% schema coverage, the baseline score 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 "Öppna en lokal fil i användarens standardeditor" (open a local file in the user's default editor), establishing a specific verb and resource. It also distinguishes itself from siblings by explicitly noting "Läser inte innehållet" (does not read the content), differentiating it from tools like willys_read_doc.

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 description provides explicit usage context: use for opening .env during setup, with the path from willys_setup. It explains the necessity (chat clients don't make file paths clickable) and notes the tool does not read content, implying an alternative for reading. However, it does not name a specific alternative tool, so it stops short of full when-not-to-use guidance.

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