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

Annotations declare readOnlyHint=false and destructiveHint=false but say nothing about repeat calls; the description fills that gap by disclosing idempotent behavior ('Saving the same generation again returns the look already saved'), which is genuinely useful for retry decisions. It does not describe error behavior for non-finished jobs or any account/profile constraints.

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 action and resource, with the idempotency caveat second. Nothing is redundant or padded.

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 one-parameter mutation with an output schema, the description covers prerequisite source, effect, and idempotency, which is what an agent needs before calling. The remaining gap is the relationship to the sibling save_my_look and behavior on an incomplete job.

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?

With 100% schema coverage and a single required parameter, the schema already carries the semantics, and the description's 'a jobId from list_my_generations' merely restates the schema's parameter description verbatim. No format, validity, or cross-tool constraint is added beyond the schema.

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 and resource ('Save a finished BeautySpark generation ... as a look in My Looks') and anchors the input to a source tool (list_my_generations), so the action is unambiguous. It does not, however, differentiate itself from the sibling save_my_look, leaving the agent to infer the distinction from the jobId input.

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?

'Finished ... generation' implies a prerequisite (the job must be complete) and 'a jobId from list_my_generations' implies where to obtain input, but neither is stated as an explicit condition. There is no guidance on when to use this instead of save_my_look, and no failure guidance for unfinished or unknown jobs.

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