list_layers

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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It states the core behavior (listing active layers) but does not explain how the session is identified via the optional state and session_id parameters, nor whether there are any side effects. This is a minor gap for a simple read-only operation, but without annotation support, more detail would be beneficial.

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, direct sentence with no unnecessary words, making it easily parseable and front-loaded.

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 simplicity of the tool and that the schema fully documents parameters, the description is sufficient to convey the tool's purpose. However, the lack of an output schema means the agent doesn't know what a list entry looks like, but for a simple listing tool this is acceptable. The description could mention that state and session_id are alternative ways to specify the session, but that is a minor omission.

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?

Both parameters are already documented in the input schema with full coverage, and the description adds no additional meaning. The baseline 3 applies since the schema handles the semantic load.

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 'List' and identifies the resource 'currently active layers' with session scope, clearly distinguishing from sibling tools that add, remove, set, or filter layers.

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 context that this tool retrieves active layers in a session, but it does not explicitly mention alternatives or when not to use it. Since sibling tools like get_map_config could also return layer information, a bit more guidance would help, but the current description is adequate for a straightforward list operation.

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