download_character_spritesheet

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

There are no annotations, so the description carries the full burden, and it does well. It discloses output contents, grid row/column semantics, cell centering, no-rescaling behavior, the output destination folder, the returned file path, and the 423 error state.

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?

Every sentence earns its place: output format, grid layout, behavior, destination, return value, alternative, and error condition. The main action is front-loaded, and the technical details are compactly organized.

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 single-parameter export tool with no annotations and no output schema, the description covers input, output format, file destination, return value, error behavior, and the sibling alternative. Nothing critical to invoking it correctly is missing.

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 character_id is already 100% covered by the schema with 'Character ID'. The description adds only indirect context (the character must be fully generated), so it meets the baseline but does not go beyond it.

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: 'Export a character as a single spritesheet', and precisely characterizes the output format (ZIP with uniform-grid PNG plus layout JSON). It explicitly contrasts with download_character_zip, making sibling differentiation clear.

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 names the alternative tool and the exact condition for choosing it: 'Use download_character_zip instead for individual frame PNGs.' It also warns that calling during character generation returns HTTP 423, telling the agent when not to call.

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