Get Active Layer

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

The description is consistent with the readOnlyHint annotation, indicating a safe read operation. It does not add extra behavioral context beyond what the annotation already provides. With annotations present, this is acceptable but not exceptional.

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, complete sentence with no unnecessary words. It is front-loaded with the essential information and earns its place.

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?

Given the tool's simplicity (no parameters, clear purpose) and the presence of an output schema (which handles return value documentation), the description is adequate. It could mention behavior when no layer is active, but the output schema likely covers that. Thus, it is mostly complete.

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 no parameters, so the description does not need to provide parameter details. Per the rubric, 0 parameters yields a baseline of 4. The schema coverage is 100% (no properties), so the description adds no further information, which is fine.

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 clearly states the action ('Get'), the resource ('active layer'), and the context ('in the QGIS layer panel'). It effectively distinguishes from sibling tools like get_layers (which lists all layers) and set_active_layer (which changes the active layer).

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 does not explicitly state when or when not to use this tool, nor does it mention alternatives. However, the purpose is clear enough for a simple getter, and the lack of parameters makes usage straightforward. Absence of explicit guidance reduces the score.

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