ass_list_fonts

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

With no annotations, the description carries the full burden. It usefully clarifies that pattern is a plain substring matched against family/style/file rather than a fontconfig expression, which prevents a real invocation error. It says nothing about cost, ordering of results, behavior when no fonts match, or required permissions.

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?

Front-loaded with the purpose, then parameters, then return shape; every sentence carries information and there is no filler. Reproducing the full return shape is somewhat redundant given an output schema exists, which keeps it short of a 5.

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 a two-parameter read-only listing tool with an output schema, the description covers purpose, both parameters, and filtering semantics adequately. The remaining gap is routing guidance relative to the other font-inspection siblings.

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 0%, so the description must define both parameters, and it largely does: pattern is a case-insensitive plain substring matched against family, style and file, and limit caps the number of entries. The default value of limit (100) and the null default for pattern are left to the schema, but the semantics are otherwise well covered.

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 ('List installed fonts') plus the optional filtering scope, so the purpose is unambiguous. It does not, however, differentiate itself from nearby siblings such as ass_fonts_used, ass_match_font, or ass_font_coverage, which an agent could easily confuse with 'list 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?

Only an implied use case ('optionally filtered by substring'). There is no statement of when to reach for this tool versus ass_match_font, ass_fonts_used, ass_fonts_with_char, or ass_font_coverage, all of which live in the same font-related family.

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