fx_screenshot

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

With no annotations, the description bears the full burden of behavior disclosure. It does mention an allowed root, but it does not state whether the tool writes a file, overwrites existing files, captures the current page, or returns nothing. This is a significant omission for a tool whose side effects and path constraints directly affect invocation safety.

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 a single sentence with no filler, but the phrasing is unclear ('View PNG to a file') and the structure buries the key behavioral information. It is concise in length but not in communicative efficiency.

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 one-parameter tool with no annotations and no output schema, the description is not complete enough. It leaves ambiguous the core action, the constraint semantics, and how the path value should be constructed. An agent would struggle to invoke it correctly or choose it over fx_snapshot.

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 schema has no description for the only parameter, and schema coverage is 0%. The description does add some meaning by indicating 'path' is a file path constrained by an allowed root, but it omits details like expected file extension, relative versus absolute format, or whether the path must already exist. It partially compensates but not fully.

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 identifies a PNG file and a path, but the phrase 'View PNG to a file' is grammatically awkward and does not clearly state whether the tool captures a screenshot, reads an existing PNG, or writes one. It does not distinguish this tool from sibling fx_snapshot, whose purpose is also image/snapshot related.

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 is given about when to use this tool versus fx_snapshot or any other sibling. The only contextual hint is the allowed-root constraint, which is a path restriction rather than a usage condition, so an agent cannot tell when this is the right choice.

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