affinity_set_document_settings

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

Annotations only say destructiveHint=true and idempotentHint=false; the description adds the actual mechanism: changing dpi, size, or transparency rewrites document setup, other settings are preserved, and background transparency silently resets to opaque unless transparent_background is passed. That is exactly the side-effect an agent needs to know before calling a destructive mutation.

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?

Four sentences, front-loaded with the action and then the side effects, with no filler. It is dense but each sentence carries information; a slight tightening of the "Supports units, dpi..." clause would make it cleaner.

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 six-parameter destructive mutation with no output schema, the description covers the return (updated settings), all parameters, the default target, and the destructive rewrite behavior. What is missing is minor: no note on whether a failure leaves the document partially rewritten, and no explicit mention that session_uuid is optional beyond the default phrasing.

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%, so the description must compensate, and it names all six parameters including the session_uuid targeting rule and the conditional effect of transparent_background. It does not explain unit semantics or the exclusiveMinimum bounds on dpi/width/height, leaving some meaning to the schema's constraints.

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?

"Change a document's setup and return the updated settings" gives a specific verb (change/set) plus resource (document setup) and enumerates the supported settings (units, dpi, width/height, transparent_background). It is clearly the mutation counterpart to affinity_get_document_settings, though it never names that sibling explicitly.

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?

"Defaults to the current document; pass session_uuid to target a specific one" gives concrete targeting guidance and a default behavior. It does not state when to avoid this tool or point at alternatives (e.g. affinity_new_document for creating rather than modifying), so it stops short of full routing guidance.

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