Start background task

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

Annotations already declare readOnlyHint=false, destructiveHint=true, openWorldHint=true and idempotentHint=false, so the safety profile is covered. The description usefully adds that the call is asynchronous and returns a task_id (no output schema exists), but says nothing about what the agent can actually modify, permission_mode effects, or quota/fallback behavior implied by the schema.

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 short sentences, zero filler, with the core purpose and the async/task_id behavior front-loaded before the parameter tip. Nothing is padded or restated from the name.

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 an 11-parameter, destructive, open-world dispatch tool with no output schema, the description is thin: it never warns that the spawned agent may write to the workspace, and it omits the session-continuation and fallback flows. The rich schema compensates for parameter details, but the behavioral gaps keep this at a minimum-viable level.

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 description coverage is 91%, so the schema already carries parameter meaning; the description only adds a selection cue for the isolation enum ('worktree for code changes'). It adds nothing for the 10 other parameters, including the undocumented permission_mode enum.

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 and resource ('Start long agent work in the background') plus the key return value (task_id), which cleanly separates it from read/observation siblings like get_task, list_tasks and wait_task. It stops short of naming a sibling or drawing the explicit contrast with a synchronous 'ask'-style call.

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?

Gives clear context for when to reach for this tool: long-running work that should run in the background rather than block, and a concrete conditional ('isolation=worktree for code changes'). It provides no explicit exclusions or named alternatives, but the usage context is unambiguous.

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