get_viewport_fov

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

Annotations already establish readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description still adds value beyond the structured data by specifying the unit (degrees) and the exact return shape, which is not available from an output schema. It does not mention error behavior for a missing/active viewport, which is the only remaining gap.

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 lines, no wasted words, and the essential content (what is read plus its unit) is front-loaded before the return-shape note. 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?

For a zero-parameter getter, the description supplies everything the agent needs: the resource, the unit, and the return shape. Since no output schema exists, stating '{ fov: number }' in the description closes that gap completely.

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 takes zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. The description correctly implies no arguments are needed by framing the call as a pure read of the active viewport.

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 (Read) and resource (current perspective FOV of the active editor viewport), including the unit (degrees) and the scope qualifier 'active editor viewport'. It is clear on its own, but it never differentiates itself from nearby siblings such as get_camera_fov, which an agent could confuse with a viewport FOV read.

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?

There is no statement of when to use this tool versus alternatives (e.g., get_camera_fov for camera assets, set_viewport_fov for the inverse operation). The agent must infer the use case from the name alone, which is a real gap given the dense viewport/camera sibling cluster.

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