Preview (inline PNG)

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

No annotations are provided, so the description carries the full disclosure burden. It does valuable work by revealing the return shape — an inline image content block plus a text summary — which is otherwise undocumented since there is no output schema. However, it never states that the operation is read-only/non-mutating, says nothing about image size or token cost for large contact sheets, and does not describe failure modes for an invalid frame or project.

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 short sentences, zero filler, and the most important fact (inline PNG the agent can see) is front-loaded. The 'all' hint and return-value note follow in descending priority order.

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 six-parameter, all-optional preview tool with no annotations and no output schema, the description covers the essential contract: what is returned and why it matters to an agent. The remaining gaps — read-only status and payload size implications of a full contact sheet — are real but secondary.

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 83%, so the schema already explains ascii, frame, scale, project, and background in adequate detail. The description's only added parameter meaning — 'all' producing a contact sheet — largely duplicates the frame property's own schema text. Baseline 3 applies when the schema does the heavy lifting.

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 ('Render the sprite as an INLINE PNG image content block') and immediately differentiates this tool from siblings like sprite_export or sprite_gallery by stressing that the image is returned inline so the agent 'can actually SEE the art'. An agent can tell this is the visual-inspection path rather than a file-writing or human-gallery path without opening any schema.

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 only usage direction is parameter-level: "Use 'all' to get a contact sheet of the whole animation." There is no explicit statement of when to call this instead of sprite_export, sprite_gallery, or sprite_inspect, and no when-not guidance. Usage is implied by the 'SEE the art' framing but never operationalized.

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