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

Annotations already establish readOnlyHint=false, idempotentHint=false, destructiveHint=false, so the mutation/concurrency profile is partly structured. The description adds genuine value by disclosing the optimistic-concurrency guard, but omits what happens on a version mismatch, permissions, or reversibility.

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 tight sentences with the operation stated first and the critical version constraint second. Nothing is wasted and the ordering is front-loaded appropriately.

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 nested, three-parameter mutation with no output schema, the description covers the operation and the concurrency contract but says nothing about failure modes, permissions, or the effect of the write. Adequate but with clear gaps.

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 coverage is 0%, so the description must carry parameter meaning. It explains only expectedSpecVersion ('required to prevent stale writes'), leaving projectId, input.layerId, and input.visibility undocumented beyond the terse schema. It partially compensates but leaves the majority of parameters unexplained.

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 pair and resource: 'Show or hide one layer in the project map.' This is clearly distinguishable from sibling layer tools (set_layer_filter, set_layer_zoom_range, update_layer_style), though it does not name any of them explicitly.

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 statement of when to use this versus alternatives such as set_layer_filter or update_layer_style, and no prerequisites or context beyond the schema. The 'expectedSpecVersion required' clause is a behavioral constraint, not usage routing.

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