get_screenshot

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

With no annotations, the description carries the full load; it does disclose the key behavioral fact that the response is an image payload rather than JSON, which matters since there is no output schema. Beyond that it is silent: nothing about whether the screenshot is captured live or read from disk, failure modes for a missing file, or access requirements.

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 nine-word sentence with the resource and return type front-loaded and zero filler. Nothing could be removed without losing information.

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?

No annotations, no output schema, and zero parameter documentation leave the definition under-specified for what should be a simple but non-obvious call. An agent cannot determine what to pass for id/file or what happens on a bad path without trial and error.

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 description coverage is 0% with two required parameters, so the description must compensate — and it does not. Neither "id" nor "file" is explained; an agent must guess that id is an instance identifier and file is a screenshot filename or path.

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?

States a specific verb and resource ("Fetch one screenshot") plus the payload type ("as an image"), which implicitly separates it from the sibling list_screenshots. It does not name that sibling outright, so differentiation is inferred from "one" rather than stated.

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 parenthetical "(visual launch verification)" implies the workflow context — call this after launch_instance to visually confirm a launch succeeded — but no explicit when-to-use/when-not or alternative is named. Usage is inferable rather than prescribed.

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