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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds some value by clarifying 'castId equals artistId' and that no duplicate actor/flag change occurs, but it does not explain what 'identity readiness' means or what the creation link is used for.

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, front-loaded with the return contents and followed by the idempotency guarantee. There is no filler, though the second sentence partly restates the idempotency annotation.

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 an output schema present, return values need not be explained, and the single required parameter is well covered. The remaining gap is the lack of sibling routing guidance against assign_actor/artist_read, but for a simple one-param read the description is largely sufficient.

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 single artistId parameter is fully documented in the schema. The description adds nothing param-specific beyond noting castId equals artistId, 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?

The description states a specific outcome — returns an artist's Film castId, identity readiness, and Film creation link — so an agent knows this is a non-mutating lookup that resolves casting identity. It does not, however, differentiate from siblings like studio_film_assign_actor or studio_artist_read, leaving the 'use as actor' framing ambiguous against the read semantics.

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 only implied: 'No duplicate actor or artist-flag change is created' signals this is the safe, non-mutating way to resolve casting, contrasting implicitly with studio_film_assign_actor. There is no explicit when-to-use, when-not, or named alternative, so an agent must infer the routing.

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