add_streaming_level

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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: the exact idempotent return path (already-present level returns added=false), the on-disk prerequisite, and the full return shape. It doesn't mention permission/auth needs, but for an editor-world mutation the added detail is solid.

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?

Purpose is front-loaded, followed by mechanics, the idempotency caveat, and the return shape. Every sentence carries information, though the inline return-object dump and stray whitespace make it slightly less tight than it could be.

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?

There is no output schema, but the description compensates by spelling out the returned fields including added and already_present. Combined with the on-disk prerequisite and idempotency note, an agent has enough to call this correctly; only the absence of any mention of ordering/interaction with other streaming-level tools leaves a minor gap.

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 100%, so baseline is 3, but the description adds meaning beyond the schema by noting that an object path ('/Game/Maps/SubLevel.SubLevel') is also accepted alongside the package path documented in the schema. That extra accepted-format detail is genuine value over the structured field.

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+resource ('Adds a saved level package to the editor world as a streaming sub-level') and then details the mechanism (creating a ULevelStreamingDynamic wrapper and attaching it to the world's StreamingLevels array). This clearly distinguishes it from siblings like get_streaming_levels, remove_streaming_level, set_streaming_level_loaded, and set_streaming_level_visible.

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 a useful precondition ('The package must already exist on disk') and notes idempotent behavior, but never names an alternative sibling or explicitly says when to choose this tool over remove_streaming_level/set_streaming_level_loaded. Usage is implied by the operation name rather than routed.

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