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 reveal the key output behavior (a single composited image for human comparison, not machine-consumable data), but says nothing about payload size, latency, or what happens when supplied slugs are invalid or unmatched.

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, zero filler, with the purpose front-loaded and the two input modes following. Every clause carries information an agent needs.

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 annotations and no output schema, the description must do more of the work itself. It adequately explains the primary slugs/query flow but leaves the presentation parameters (style, theme, limit) and the failure modes of a purely visual tool undocumented.

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?

Adds real meaning beyond the schema for two of five parameters: slugs come 'from an earlier tool call' and query is a search-and-preview shortcut. The style, theme, and limit parameters are left entirely to the schema, and style/theme have enums but no descriptions, leaving the 60% coverage unresolved.

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 ('Render candidate Digche icons') plus the output form ('as a single image') and the reason ('so a person can compare them before choosing'). This meaningfully distinguishes it from get_icon_svg (a single SVG fetch) even though no sibling is named explicitly.

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?

Gives two concrete invocation paths: pass slugs from an earlier tool call, or pass a query to 'search and preview in one step', which clarifies the relationship to search_icons. It stops short of stating when not to use this (e.g. when you only need markup, use get_icon_svg).

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