kitty_set_font_size

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

With no annotations provided, the description carries the full burden. It discloses a key behavioral trait: all sub-windows in the same OS window share font size. However, it omits details on destructive nature, permissions, or error handling, leaving some transparency gaps.

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?

The description is extremely concise at two sentences, with no redundant information. The first sentence establishes purpose and a key behavioral point, and the second provides complete parameter guidance. Every word 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?

Given the simplicity of the tool (2 parameters, no output schema, no nested objects), the description covers the essential aspects: what it does, how to specify size, and the sharing behavior. It is complete enough for an agent to use correctly, though it could mention return status or confirmation.

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 100% with both parameters having descriptions. The description adds significant value beyond the schema by explaining the exact format of the size string (relative changes, absolute, reset) and the effect of the 'all' parameter, which is only briefly described 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 clearly states the verb 'Set' and resource 'font size in the active OS window', providing a specific action and context. It also distinguishes behavior by noting that all sub-windows in the same OS window share the same font size, which differentiates it from siblings like kitty_resize_window or kitty_set_spacing.

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 explains how to use the tool with clear formatting for the size parameter ('+N', '-N', number, '0'). It implies the context of active vs all OS windows via the 'all' parameter. However, it does not explicitly state when not to use this tool or compare it to alternatives like kitty_set_spacing.

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