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

Annotations only declare the generic write profile (readOnly=false, destructive=false, idempotent=false); the description adds substantial specifics beyond that — lineage fields, segment versions pinned at duplicate time, null record_count, immediate active status, and the 'creator' scope requirement. This is exactly the mutation, side-effect, and auth context an agent needs before calling.

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 action and followed by the state/lineage facts an agent needs; there is no filler. It is dense and multi-clause, which slightly raises parsing cost, but every clause carries information.

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 non-idempotent mutation with a trivial three-parameter schema and an output schema present, the description covers prerequisites (creator scope), resulting state (active, null count), lineage semantics, and the natural follow-up call. Nothing needed to invoke it correctly is missing.

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 all three parameters (name with its default, audience_id, optional campaign_id) are documented inline, so the schema does the heavy lifting. The description adds behavioral color around the campaign link but no new syntactic or format meaning for the parameters themselves, so the baseline 3 applies.

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 ('Create a duplicate') and resource ('existing audience'), then enumerates exactly what is copied (segment_ids, excluded_segment_ids, set_logic) and what lineage is recorded (parent_audience_id, derived_from). An agent can distinguish this from create_audience or duplicate_segment without opening any schema.

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 operating context: the copy is immediately active, starts with record_count null, and the agent should call recount_audience for a fresh count; linking to a campaign is framed as optional. No explicit 'do not use this when...' or direct contrast with create_audience, so it stops short of a 5.

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