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

Annotations are all false, so the description carries the disclosure burden. It adds meaningful behavioral context: each result fills a slot recorded in avatar_creator.view metadata, and only completed generate_avatar results are eligible. It does not discuss side effects like overwriting or reversibility, but for a save operation with no destructive hint, this is reasonably transparent.

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?

Three sentences, no wasted words. The lead sentence states the purpose, the second explains parameter roles, and the third adds usage timing and eligibility. Information is front-loaded and easy to scan.

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 3 params, no output schema, and no nested objects, the description covers the key operational constraints: when to invoke (after generation, user choice), eligibility (only generate_avatar results), and how results map to slots. It does not state what the response returns (e.g., saved avatar ID), but given lack of output schema, this is a minor gap.

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 coverage is 100%, so baseline is 3. The description adds value by clarifying the roles of generation_result_id as 'identity-anchor result' and additional_result_ids as 'view results' that fill slots in avatar_creator.view metadata. This goes beyond the schema's per-parameter descriptions, which individually explain what the IDs are but not their functional relationship in the saved avatar.

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 verb ('Save') with a specific resource ('completed generate_avatar image results') and outcome ('as one reusable avatar/model'). It clearly distinguishes from sibling tools by restricting to generate_avatar results, unlike upload_avatar_from_chat_file or create_avatar_from_references.

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?

Provides explicit timing context: 'Use only after generation finishes and the user chooses the candidates.' Also includes an exclusion: 'Normal text-to-image results are not eligible.' While it doesn't name alternative tools, the guidance clearly indicates when to use and when not to use, differentiating from related file-upload or reference-based avatar creation tools.

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