affinity_add_text

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

Annotations already declare this is a non-read-only, non-idempotent, non-destructive mutation. The description adds that a new frame is created using the document's default text style, which is useful context beyond the annotations. It does not cover the return value, whether the new frame becomes selected, or what happens if the text overflows the frame.

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 sentences, no filler, with the core action and coordinate contract front-loaded and the targeting override last. Every clause carries information.

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?

The description covers inputs and target selection, but with no output schema and no annotation detail on results, an agent still does not know what the tool returns or whether the frame is selected or styled beyond defaults. Adequate but with clear gaps for a mutating creation tool.

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 0%, so the description carries the full burden and does it reasonably well: it names x, y, width, height, and text, fixes the unit as pixels, and explains session_uuid's targeting role. It does not state that width/height define the frame box rather than the text bounds, which is an inference the agent must make.

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 gives a specific verb and resource ('Add a text frame containing text') plus the coordinate model, which separates it from affinity_add_shape and affinity_place_image. It does not explicitly name those siblings, so an agent must still infer the distinction.

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 states the default target (current document) and the override condition ('pass session_uuid to target another'), which is genuine routing guidance. It says nothing about when to prefer affinity_add_shape or affinity_execute_script for text, and no preconditions are given.

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