Create text crawl

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

Annotations provide readOnlyHint=false and destructiveHint=false, which align with the description's 'Build' action. The description adds valuable context beyond annotations: it explains internal implementation (textTOP, transformTOP, EXPRESSION parameter), the looping behavior, the 'out' nullTOP handle, and explicitly flags risks for typewriter mode ('EXPERIMENTAL — unverified') and bg_alpha par probing ('UNVERIFIED'). This transparency about potential instability is exemplary.

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 detailed but dense, covering modes, mechanism, loop behavior, output handle, sibling differentiation, and return format. While longer than typical, every sentence contributes useful operational information. It is organized from high-level purpose to implementation to differentiation, though a slight rewrite could tighten the technical explanation.

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?

With 11 parameters and no output schema, the description compensates well by explaining internal topology, output handle, and return JSON structure. It covers key behavioral aspects like continuous wrapping and the experimental typewriter mode. Minor gap: no explicit example or mention of typical resolution/defaults, but overall it is complete enough for an agent to invoke correctly.

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%, providing baseline 3. The description adds meaning by explaining the role of mode (three animation styles) and loop (continuous vs one-shot), and by describing the return JSON fields. It also clarifies semantic nuances like 'speed is a fraction of output resolution per second' and 'use \n to separate lines', which go beyond individual parameter descriptions.

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 tool's function: 'Build a multi-line animated text crawl / ticker / credits roll / typewriter reveal inside a self-contained baseCOMP.' It enumerates three specific modes (crawl_horizontal, roll_vertical, typewriter) and explicitly differentiates from sibling tools create_kinetic_text and create_text_overlay. The verb 'build' plus the resource (baseCOMP) makes the purpose unmistakable.

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 provides explicit when-to-use guidance: 'Differs from create_kinetic_text (single-string flash/pulse/slide) and create_text_overlay (a static, non-moving caption/title); this tool handles multi-line copy, continuous scrolling, and character-reveal.' It also explains how each mode is used (e.g., roll_vertical uses \n to separate lines) and notes the loop behavior for continuous scrolling.

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