ass_add_style

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

With no annotations to lean on, the description carries the full burden and delivers: verbatim storage rules ('/48.0' becomes 48), colour normalization, pre-write validation constraints (font_size positive, alignment 1-9, border_style 1 or 3), the destructive semantics of overwrite=True (fields revert to defaults), and the relative_to/Format-line 'ignored_fields' edge case.

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-loads the core create/replace action and the overwrite distinction before the detail paragraphs. Dense and largely waste-free, though the validation and returns blocks could be tightened.

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?

Covers the hard parts an agent needs: overwrite semantics, validation, the Format-line caveat, and the return shape. With a declared output schema, the explicit return documentation is a bonus rather than a necessity, and the partial parameter coverage is the only real 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 description coverage is 0% across 26 parameters, so the description must compensate. It adds real validation meaning for font_size, alignment, border_style, margins, colours, overwrite, and relative_to, but leaves the majority (bold, italic, outline, shadow, scale_x/y, spacing, encoding, angle, font, underline, strike_out) to inference from titles/defaults.

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 concrete verb+resource ('Create a style, or replace an existing one of the same name') and immediately distinguishes itself from the sibling ass_update_style. An agent knows exactly what this tool does versus its neighbors without opening any 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?

Explicitly names the alternative ('use ``ass_update_style`` to change a few fields and leave the rest alone') and gives the precise condition under which overwrite replaces versus preserves fields. This is the when/when-not/alternative pattern at its best.

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