Set the UI font (verified)

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

No annotations provided, so the description bears the full burden. It discloses that the tool mutates state ('Change') and that it triggers a verification step. However, it does not mention side effects, permission requirements, error handling (e.g., invalid font names), or whether the change persists. This is minimal coverage for a mutation tool.

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?

One concise sentence that is front-loaded with the core action, then the source and verification. Zero filler, every word is functional.

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?

Given one parameter, no output schema, and no annotations, the description covers the essential flow but omits return value expectations and error conditions. The reference to font_list and font_current provides context, yet an agent is left to infer what happens on success or failure. This is a simple tool, so the gap is moderate but acceptable at a baseline level.

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?

The schema already provides 100% coverage with the parameter description 'Font name from font_list'. The tool description reinforces this by saying 'using a value from font_list', which adds a bit of procedural context but does not introduce new semantics beyond the schema. Baseline 3 applies.

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?

Description states a specific verb 'Change', the resource 'Omarchy's font', and the source of valid values ('from font_list'). The verification step is also mentioned, clearly differentiating this from font_list (listing) and font_current (checking). The title adds the 'UI' context, making the purpose unambiguous.

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?

The description implies a workflow: obtain a value from font_list, then set the font, then verify with font_current. This gives the agent a clear sequence and signals the dependence on font_list for valid names. However, it does not explicitly state when not to use this tool (e.g., 'use font_current to view, font_list to list'), so it misses explicit exclusions.

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