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

Annotations already declare readOnlyHint=true and idempotentHint=true, but the description adds significant behavioral nuance: re-listing does not extend expiry, generations are billed when they complete, and downloads remain available even if the response never arrived. This goes well beyond the structured hint data and is consistent with it.

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?

The description is long but every sentence earns its place: purpose, recovery scenario, billing/expiry caveat, source scope, full return payload breakdown, and cost note. It is front-loaded with the primary action and structured logically from simplest use case to detailed output semantics.

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 tool that lists recent generations, the description is remarkably complete. It covers cost, ordering (newest first), what fields are returned, how lineage can be reused via create_reference, and the fact that the promptJSON enables reproduction. The presence of an output schema further reduces the burden, but this description would be nearly sufficient even without it.

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?

The single parameter 'limit' is fully described in the input schema (default 5, no ceiling, read total to detect truncation). Since schema coverage is 100%, the description does not need to add parameter detail, and it correctly focuses on output rather than repeating the schema. 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 opens with a specific verb+resource: 'List your recent successful generations and return their download URLs again.' It immediately distinguishes itself from siblings like generate_image_set by focusing on retrieval/recovery rather than creation, and even names the recovery use case explicitly.

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?

It states exactly when to use this tool: 'Use this to recover a generation whose result message was lost (for example a dropped connection mid-call).' It also gives important context about billing and expiry, and mentions that generations from the logospell.com page appear here too, helping an agent decide when this is the right call.

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