Build HTML gallery player

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

With no annotations, the description carries the full behavioral burden. It does useful work by declaring the output is fully self-contained, offline-capable, and sandbox-preview-safe, but it never says whether a file is written to disk, where it lands, whether an existing file is overwritten, or what is returned to the caller.

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?

Two sentences, front-loaded with what gets produced, then the feature list in parentheses. Dense but every clause conveys concrete content; no filler or restatement of the tool name.

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 no output schema and no annotations, the description must hold everything, and it does adequately describe the returned artifact and its runtime properties. It falls short on the write side — path resolution, overwrite behavior, and the meaning of four undocumented parameters — which matters for a tool that produces a file.

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 only 33%, and the description does not compensate: dir, scale, title, background, and the base name parameter are never explained in terms of effect on the generated HTML. The only implicit parameter signal is the base64/feature list, which hints at what the output contains rather than what each input changes.

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?

States a specific verb and resource ('Write a fully self-contained HTML animation player') and enumerates the artifact's contents (base64 PNGs, playback controls, onion skin, zoom, palette swatches, frame tags). That goes well beyond a tautology, though it never names the nearest siblings (sprite_export, sprite_preview) to distinguish itself.

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?

There is no explicit when-to-use or when-not guidance, and the obvious alternatives in this toolkit — sprite_preview and sprite_export — are never mentioned. 'Works offline and in a sandboxed preview' sketches a use context but does not tell an agent when to pick this over exporting or previewing by another route.

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