open_image

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

Annotations only provide basic hints (readOnly=false, destructive=false, openWorld=false), so the description adds meaningful behavioral context: it opens a persistent view window, returns view id/dimensions/FITS keywords, and keeps the window available for later tools. No contradiction with annotations exists.

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?

Two concise sentences front-load the core action and format list, then add return values and persistence. Every clause earns its place with no redundancy or 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?

For a simple two-parameter tool, the description is sufficiently complete: it covers the operation, supported formats, return values, and persistence for downstream tools. There is no output schema, so mentioning the return contents is valuable; only minor details like path requirements or default view naming are absent.

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 50%: the 'id' parameter has a description, while 'path' has none. The description partially compensates by listing accepted file formats (FITS/XISF/TIFF) and implying 'path' identifies an image file, but it does not add detail about path semantics or the optional id behavior beyond the schema.

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 states a specific verb and resource: 'Open an image file ... in PixInsight as a view.' It also names supported formats and distinguishes the operation from siblings by emphasizing it opens a view rather than processing or saving data. The return values and window persistence further anchor its identity.

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 clearly implies when to use the tool: when an image file needs to be opened as a view for subsequent tools, explicitly noting 'The window stays open for later tools.' It does not name alternatives or exclusions, but the intended context is evident from the phrasing and sibling list.

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