get_font_list

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

No annotations are provided, so the description carries the full burden and does meaningful work: it discloses the returned fields, the conditional presence of variationSettings (only for variable fonts), and the inclusion of usage counts. It does not state read-only status explicitly or mention auth/permission needs, but for a List operation the behavioral picture is largely conveyed.

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 tight sentences with zero filler; the scope and return content are front-loaded, and the cross-reference comes last. Every clause earns its place.

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 cover purpose, scope, and returns, which it does. It leaves the read-only nature and default scope only implicit, but for a simple one-parameter list tool the definition is essentially complete.

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 0%, so the description must explain the single parameter, and it does: rootNodeId is framed as selecting a 'subtree', implying its scoping role and that omission defaults to the current page. That is genuine meaning beyond the bare string type in 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?

The description names a specific verb (List) and resource (distinct fonts) and pins down the scope precisely: 'the current page or a rootNodeId subtree'. It also enumerates the return shape (family + style, variationSettings, usage counts) and references the complementary sibling get_font_variation_axes, so an agent can distinguish it from that tool without opening a schema.

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?

It gives clear context for when the tool applies (current page vs. a rootNodeId subtree) and directs the agent to a related tool for axis inspection. However, it stops short of explicit when-not guidance or naming a true alternative, since no competing font-listing tool exists among the siblings.

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