Paint: Text label

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

Annotations already declare the safety profile (readOnly=false, destructive=false, idempotent=false), so the bar is lower, and the description adds real behavior: a fixed 5x7 ASCII font, transliteration (or error) for non-ASCII, no font files required, and undo interoperability. It does not mention permissions or error semantics, but the added context is substantive.

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 short paragraphs, front-loaded with purpose and then behavior; each sentence carries weight. The second paragraph's 'layers, filters and undo work the same for every drawing tool' is slightly generic boilerplate, but it is brief and useful.

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 19-parameter mutation tool with no output schema, the description covers purpose, font behavior and a few key params, but leaves most parameter semantics and error/permission behavior unexplained. It is adequate but incomplete given the tool's complexity.

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 low (42%), so the description must compensate, and it does explain scale (pixel multiplier), align/valign (anchoring around x,y), max_width (wrapping) and unicode behavior. However many of the 19 parameters (color, opacity, outline, outline_color, blend, line_spacing, letter_spacing, preview/preview_size) get no meaning in the description, so the coverage gap is only partly closed.

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 and resource ('Writes text with the built-in 5x7 pixel font') and immediately identifies the distinguishing trait versus the other paint_* drawing tools, which draw shapes/pixels rather than text. An agent can pick this out from paint_brush or paint_rect without opening the schema.

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 gives context -- target a canvas created with paint_canvas and optionally a layer index, and notes layers/filters/undo behave uniformly across tools -- but never states when to use paint_text instead of a sibling or any exclusion conditions. Usage is implied rather than explicit.

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