ass_fonts_with_char

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

No annotations are provided, so the description carries the full burden. It discloses the required input constraint ('char must be exactly one character') and the exact return shape, and the phrasing implies a read-only scan of installed fonts. However, it says nothing about the scope/cost of scanning all installed fonts, permissions, or failure behavior for unmapped characters.

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: the query intent is front-loaded, followed by the input constraint and the return shape. No filler, no redundancy.

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 single-parameter query tool with an output schema present, the description covers the input constraint and the returned fields, so an agent has enough to call it. It stops short of explaining when this is preferable to sibling font/glyph tools, leaving a small completeness gap.

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% – the schema gives only a bare 'string' type for 'char'. The description compensates by stating the semantic constraint that 'char' must be exactly one character, which is real meaning beyond the schema. It does not clarify surrogates, whitespace, or empty-string handling, so not a 5.

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 states a specific query intent: which installed font families contain a given glyph. That is a clear verb-plus-resource framing (query installed fonts by glyph presence). It does not explicitly distinguish itself from close siblings like ass_glyph_check or ass_font_coverage, so it lands at 4 rather than 5.

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?

There is no guidance on when to reach for this tool versus ass_list_fonts, ass_font_coverage, ass_glyph_check, or ass_fonts_used. Usage is only implied by the purpose statement; no conditions or alternatives are named.

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