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

Beyond annotations (readOnlyHint=false, destructiveHint=false), the description discloses that the operation returns a casting_id that preserves identity and provenance across takes, and restricts input to seeded/private actors. This adds behavioral context about persistence without contradicting annotations.

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?

Single sentence with a front-loaded verb, clear object, and return value. No filler or redundant restatement of the tool 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 a six-parameter mutation with no output schema, the description gives the core action and return value but omits preconditions, repeated-cast behavior, and meaning of optional fields like notes/source_url. Sibling delete_casting hints at lifecycle but the description itself leaves these gaps.

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 only 17% (only character_description has a description). The description does not explain notes, source_url, or the relationship/semantics of actor_id/story_id beyond 'seeded or private actor' and 'one story character', so it fails to compensate for the low schema coverage.

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?

Description uses specific verb 'Bind' with clear resources: 'seeded or private actor' to 'one story character'. It distinguishes from sibling tools like casting_roster (listing), delete_casting (removal), and audition by describing the act of assigning an actor to a character and returning a casting_id.

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?

The phrase 'Bind a seeded or private actor to one story character' implies the tool should be used when assigning such an actor to a character, and 'across takes' suggests persistence. However, no explicit when-to-use/not-use guidance or alternatives are mentioned.

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