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

Beyond the annotations, it discloses real operational context: the non-Pro cap of one list, the OAuth scope required, and the idempotency contract of reusing requestId on retry, which meaningfully extends the terse idempotentHint flag. It stops short of describing failure behavior when the tier limit is hit or what a duplicate requestId returns, leaving some ambiguity for a mutation the agent may retry.

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?

Four short sentences, front-loaded with the action and followed by constraints and prerequisites in a sensible order. The closing "Account tier limits apply" is largely redundant with the earlier non-Pro cap sentence and could be dropped without loss.

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 flat three-parameter creation tool with an output schema (so return values need no explanation) and annotations covering the safety profile, this covers actionable prerequisites and the idempotency contract well. The main gap is the absence of any guidance on the title/description fields and on the expected outcome when the account tier limit is already reached.

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 0%, so the description must carry parameter meaning, and it does so only for requestId, explaining uniqueness and retry reuse semantics that the UUID format field cannot convey. The title and description parameters get no treatment at all, so the agent must rely entirely on min/maxLength constraints for two of three params.

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?

"Create one list" states a specific verb and resource, and the singular "one list" plus tier-limit sentence makes the cardinality constraint clear. It does not explicitly distinguish itself from sibling mutators like daylily.create_listing or daylily.update_list, but the noun 'list' versus 'listing' is discernible from the name itself.

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 description supplies prerequisites (connected account, catalog:write scope) and an account-tier constraint, which tells the agent when the call will succeed. It never says when to prefer this over alternatives such as daylily.update_list, nor does it state what to do if the account is already at its list limit.

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