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

Annotations only declare readOnly=false, idempotent=false, destructive=false, openWorld=false; the description adds substantial behavior beyond that: hiding a part layer leaves territories unchanged, missing point layers are re-pushed (status=refreshed, render_ack), unsupported hides return HIDE_NOT_SUPPORTED with do_this_next, and the legend checkbox is a single-tab workaround.

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 scoping and routing intent is front-loaded, but the body is a single very dense run-on block mixing input selection, per-kind behavior, and return codes, making it hard to scan. Most sentences earn their place, but the packaging is not concise.

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 10-param mutation tool with an output schema and annotations, it stops short of re-explaining return values yet still discloses the key outcome codes (refreshed, render_ack, blocked_by, HIDE_NOT_SUPPORTED). The main gap is the three unmentioned concurrency/merge parameters.

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?

With 0% schema coverage and 10 params, the description carries the burden and covers the key ones: map_session_id (marked preferred), ts_handle, ts, overlay_kind (with its enum values), overlay_id, route_id ('targets one'), and implicit user_request. It leaves merge_strategy, expected_revision, and expected_content_hash undocumented, so it is strong but not complete.

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 states a specific verb pair (shows/hides), the resource (overlays on the open map), and enumerates the overlay kinds it handles (part_layer, point_layer, tal, route). It also distinguishes itself from siblings like delete_point_layer and configure_map by routing those cases 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?

It gives concrete when-to-use conditions: plain request ('add US zip codes', 'hide the zips') or overlay_kind+overlay_id, and states prerequisites ('point layers must already be ingested', routes must exist or blocked_by=needs_route). It names alternatives for cases it doesn't handle (delete_point_layer, configure_map).

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