List available fonts

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

Annotations already mark it read-only, so the safety profile is known. The description adds valuable behavioral context beyond the schema: a font that isn't in this list silently does nothing in dependent tools, and the returned names are the exact values expected by the setter tools. This over-delivers relative to the annotation baseline.

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 tightly written sentences, with the main purpose in the first and the practical caveat in the second. No filler, no repetition of schema content; 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?

For an optional-parameter read-only listing tool, this is complete: it states what is listed, the exact naming detail, the intended consumers, and a critical failure mode. No missing information prevents an agent from calling it correctly, and no output schema is required for a simple listing.

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 description coverage is 100%, with limit and query already documented (default 80, case-insensitive substring), so the description doesn't need to add parameter detail. It adds only contextual value about how the returned names are consumed, not new meaning for the parameters themselves. Baseline 3 is appropriate.

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'), a concrete resource (fonts installed for After Effects), and the key output detail (PostScript names). This distinguishes it from every sibling tool; no other sibling claims font listing.

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 explicitly tells the agent when to use this tool: before ae_add_layer and ae_set_text, because those tools expect PostScript names. It lacks an explicit 'when not to use' or alternative-tool exclusion, but there is no sibling font-listing tool, so this is clear context.

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