Suggest fonts that fit the design

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

Annotations already cover the safety profile (readOnlyHint/destructiveHint/openWorldHint), so the bar is lower; the description adds real behavior beyond them — partial reads capped at 5,000 layers or 5 s, `scanned` reporting whether the read was whole, and the two-call apply path via figma_set_text_properties. 'Reads only' merely restates the annotations.

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?

Information-dense and front-loaded with the core purpose; every clause carries a fact. The em-dash-packed single paragraph and backtick-heavy style make it slightly dense to scan, but there is little genuine filler.

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 largely meets it: ranked pairings with exact style names, a type scale, plus `consistency`, `scanned`, and `applyPlan` heading/body node ids. Enough for an agent to call it and act on results, though the shape of applyPlan and consistency is only sketched.

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 100%, so 3 is the baseline, but the description adds rationale the schema lacks: it explains how `mood`/`use` drive the ranking, why to set `nodeId` (fit one frame when a page is too large to read whole), and the file-selection purpose of `session`. This goes beyond the per-field text.

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+resource (suggests heading/body font pairings) and the exact inputs it derives them from (existing fonts/sizes plus available fonts). It is clearly distinguishable from figma_get_fonts, which merely lists available fonts.

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 clear context: use it to pick typography like a designer, keep the existing font when `consistency` flags one 'unless changing it is the point', and pass nodeId to scope a partial page read to one frame. It does not name sibling alternatives for listing fonts or applying styles, so it stops short of explicit when-not guidance.

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