Open file

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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the safety profile is covered structurally, but the description adds nothing: it doesn't explain what 'open' actually does, whether it launches an external process, or what side effects openWorldHint implies.

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?

A single short sentence is technically concise, but it is under-specified rather than efficient—there is no front-loaded useful information to structure.

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 an open-world, non-read-only tool with an undocumented required parameter and no output schema, the description supplies none of the information an agent needs to call it correctly or predict its effects.

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?

There is one required parameter 'file' with 0% schema description coverage and no type information; the description says nothing about it, so an agent cannot tell whether it expects a path, URL, or identifier.

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?

'Invoke the open_file operation' only restates the tool name; it does not say what resource is opened, in what sense (OS handler launch, file read, stream), or how it differs from siblings like watch_media or download_media.

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?

No guidance whatsoever on when to call this versus the ten sibling tools (download_media, watch_media, media_downloader_watch, etc.), nor any prerequisites or exclusions.

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