open_file

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

Discloses key behaviors: app execution vs xdg-open, path resolution, X11/D-Bus handling for GTK apps, and that it does not open new instances. Lacks details on error handling or file existence checks, but overall satisfactory given no annotations.

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 compact sentences plus a note, each serving a distinct purpose: core function, app behavior, path handling, alternative tool, GTK specifics. Efficiently packed with no redundancy.

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?

Covers main functionality, parameter usage, alternative tools, and special handling. Does not describe output (mitigated by output schema) or error cases. Adequate for a file-opening tool with moderate complexity.

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 has 0% description coverage; description compensates by explaining filepath (relative path resolution), app (optional executable), and partially instance (implied as instance number). Instance parameter could benefit from more detail, but overall good addition.

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?

Description clearly states verb ('Open'), resource ('local file'), and context ('ON an existing instance's display'). It explicitly negates new instance creation and distinguishes from upload_file for browser uploads. Sibling differentiation is strong.

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 says when to use upload_file() instead for browser uploads, references launch_app for GTK handling, and explains path resolution relative to instance staging folder via list_files. Provides clear contextual alternatives.

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