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

No annotations, so the description carries the full burden; it does add real behavior context by noting that 'context' may be written in English or Persian and that results are ranked, plus that source can come from any library. It omits the return shape, the default candidate count, and whether ranking is deterministic — gaps a no-annotation mutation-free tool still needs covered.

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 the core action and scope, followed by a single actionable tip. No filler and nothing redundant with the schema.

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 five parameters, no annotations, and no output schema, the description does not say what a 'replacement' result contains (ranked names? library? preview?) or what the default limit is. It covers the essential calling intent but leaves an agent guessing about the response.

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 60%, so baseline is 3. The description does add semantic value for two parameters: enumerating valid sourceLibrary values and stating the context language flexibility. However, preferredStyle (9 enum values, default 'Linear') and the sourceLibrary parameter's relationship to sourceIcon are never explained beyond the schema.

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 pair and resource ('find and rank ... replacements' for an icon) and names the supported source libraries (Lucide, Heroicons, Material Symbols, Font Awesome). It is clearly distinguishable from search_icons or list_categories by its replacement framing, though it never names a sibling explicitly to route the agent.

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?

Adds one genuine usage hint — supply UI context for a better match — but says nothing about when to prefer this over recommend_icons or search_icons, and no exclusions or prerequisites are given. The usage guidance is implied rather than stated.

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