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

Annotations already declare readOnlyHint=true and openWorldHint=false, so "Read-only" adds nothing. What does earn credit is behavioral context the annotations cannot express: the download links work without sign-in for 24 hours, so expiry/portability matters, and the description says how to fetch the file in a shell versus handing the URL to the user.

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?

Purpose is front-loaded in the first clause, and every sentence is actionable. It does run long as a single undifferentiated paragraph mixing return shape, URL parameter hacking, and shell mechanics, which makes the operational details harder to scan for a two-parameter read tool.

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, the description carries the return-value burden and does it well: it names the fields (preview, size, palette, png_url, sheet_url), explains the &frame/&scale/&cols modifiers, and covers the include_pixels extra. The only real hole is the unexplained asset_id, which the schema also leaves bare.

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 50%: include_pixels is documented in the schema and only echoed here ("palette-index grid"), while asset_id — the sole required parameter — is never described in either place, with no format, provenance (list_sprites/save_to_library), or failure behavior. The description had the burden of compensating for the gap and did not.

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?

"Show one sprite from the user's SpriteForge library" gives a specific verb (show/fetch one) and resource (a single library sprite), and the singular framing distinguishes it from list_sprites. The description then enumerates exactly what comes back: preview image, size, palette, download links.

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?

Usage is only implied: the singular "one sprite" plus a required asset_id signals this is for fetching a known asset, and the link-lifetime note implies it's for handing assets to the user. There is no explicit statement of when to prefer this over list_sprites or open_sprite_in_editor, and no guidance on what to do with an unknown asset_id.

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