gallery_grab_still

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

No annotations are provided, so the description carries the full burden. It discloses that the tool captures a snapshot, adds it to the current album, returns True on success, and may require the Color page with a valid viewer image. This addresses action and failure conditions, though it does not delve into other side effects or permissions.

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 front-loaded and efficient at four sentences. However, the first sentence ('Grab a still from the current viewer into the current album') is largely redundant with the second sentence ('Captures a snapshot ... and adds it to the current still album'), so it is not perfectly concise.

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 no-parameter tool with an output schema, the description is complete: it explains what the tool does, how it works, what it returns, and a key prerequisite. The sibling gallery tools provide additional context, and nothing important is missing.

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 tool has zero parameters and an empty input schema. The description correctly includes no parameter details, matching the baseline 4 for 0-param tools.

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 uses a specific verb and resource: 'Grab a still from the current viewer into the current album.' It clearly distinguishes this tool from siblings like gallery_get_stills (listing) and gallery_import_stills (importing) by specifying source (viewer) and destination (current album), and references the Color page 'Grab Still' button.

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 clear usage context: it captures the current viewer display and adds it to the current still album, equivalent to the 'Grab Still' button. It also states the prerequisite of being on the Color page with a valid viewer image. It does not explicitly name alternatives or exclusions, but context is clear enough.

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