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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description still adds real value by stating there is no charge ('Free; changes nothing and charges nothing') and by naming the pricing/version/capacity fields the call surfaces, which the agent would otherwise not expect from a 'list roster' tool.

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?

A single sentence, front-loaded with the primary payload and the secondary offer details, followed by a short cost/side-effect clause. Nothing is wasted and nothing essential is deferred.

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?

With no parameters and no output schema, the description carries the burden of describing returns, and it does name the roster plus the pricing tuple. It is slightly thin on what a roster entry contains and on whether the offer is per-actor or global, which matters for a zero-input call.

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?

Zero parameters, so there is nothing to disambiguate; baseline 4 applies. The description correctly adds no param noise.

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?

Specific verb 'Return' with a clearly scoped resource ('your owned fictional presenter roster') plus a second stated payload (live creation offer: prices, pricing version, capacity). It is easy to distinguish from soclo_actors_create or soclo_actors_remove, though it never explicitly contrasts with soclo_actors_current, which is the nearest ambiguous sibling.

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?

Usage is implied by 'roster' (list what you own) rather than stated, and there is no explicit 'use this instead of X' routing. The agent must infer the list-vs-current distinction from the tool name alone.

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