player_custom_avatar

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

Despite no annotations being provided, the description fully discloses behavior: metadata-only calls download nothing, rendered art omits level text, badges, and exemplar overlays, clients must not add level text, and the operation requires no credentials and performs no game writes. This exceeds typical transparency and leaves very little behavioral ambiguity.

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 information-dense with no filler. It leads with the core action, then details rendering behavior, exclusions, client policy, and safety properties. Every sentence earns its place while keeping the full description manageable.

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 2-parameter tool with no output schema and no annotations, this description is remarkably complete. It covers the returned data shape (numeric level, appearance selections, badges), render options, image-exclusion behavior, legacy vs custom scoping, credential requirements, and side effects. An agent has enough information to make the correct call, including how to handle the returned data.

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 0% schema description coverage, the description must compensate for both parameters. It does explain `render` thoroughly: 'Set render=true to compose the official artwork layers into a PNG; metadata-only calls download no images.' However, it never explicitly explains the `name` parameter; an agent must infer that it is a player or avatar identifier. The semantics are adequate for one parameter but incomplete overall.

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 and resource: 'Read the saved custom avatar-builder settings from the official player_avatar endpoint.' It further differentiates the tool by directing agents to use it 'for the custom character, not the legacy RUNI/profile image redirect,' making its scope unambiguous relative to siblings such as player_avatar.

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 gives clear situational guidance: 'Set render=true to compose the official artwork layers into a PNG; metadata-only calls download no images.' It also states an exclusion: use this for the custom character, not the legacy RUNI/profile redirect. However, it does not explicitly compare with sibling tools like player_avatar beyond referencing the same endpoint, leaving some selection nuance to the agent.

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