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

Annotations only supply readOnlyHint=true, so the description earns credit for disclosing transcript isolation semantics and the default iteration budget. However, the iteration default (20) and share_context_with isolation are already restated in the schema descriptions, so the incremental behavioral value is partly duplicative. No contradiction: dispatching a worker is itself a control operation, though a spawned manifest_author can indirectly mutate state.

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?

Front-loaded with the core action, then the conditional guidance, then behavioral facts about budget and isolation. Every sentence carries distinct weight; nothing is filler.

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 6-param tool with nested scope and no output schema, the description covers the decision logic and worker behavior well. It stops short of describing what dispatch returns (an id? a handle?) or how to collect a subworker's result, which leaves a small 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 description coverage is 100% and the enum already lists and explains every worker_type. The description's mention of planner_opus and registry_prober is consistent with the schema but adds no syntax or constraint detail beyond it, so the baseline 3 is appropriate.

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 (spawn) and resource (a focused child agent/subworker) with a clear scoping qualifier (narrowly-scoped task). The concept is distinct from anything in the sibling list, so an agent can tell this is the delegation mechanism rather than a direct action tool.

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?

Explicitly enumerates three conditions for use (parallelisable work, narrow tool list, different model) and states the default is single-loop execution in the parent, with 'reach for subworkers when one of those three conditions clearly applies.' This is textbook when-to-use / when-not guidance.

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