affinity_new_document

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

Annotations already declare a non-read-only, non-destructive, non-idempotent mutation. The description adds useful behavior beyond that: save_as is optional and the tool returns a session UUID for later tools. It stops short of explaining overwrite behavior when save_as targets an existing file, which would be useful for a mutation tool.

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, front-loaded with the core action and modes, then the return value. Every clause carries useful information and nothing is repeated from structured fields.

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 document-creation tool with annotations and no output schema, the description is nearly complete: it covers creation modes, optional saving, and the returned session UUID. The main omission is what happens if save_as points to an existing document.

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?

With schema coverage at 100%, the baseline is 3, but the description adds meaningful semantics not obvious from the schema: preset examples such as 'A4', 'IG Post', and 'Icon', and the anyOf choice between preset mode and explicit dimension mode. It also clarifies that save_as is optional. The dpi parameter is left unexplained, keeping it from a 5.

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 uses a specific verb and resource ('Create a new Affinity document') and clearly separates creation from opening existing documents. It also states the two construction modes and the returned handle, so an agent can identify the tool 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 clearly explains the two valid creation modes: a named preset or explicit width, height, and units, with optional save_as. It does not explicitly name when to use this instead of sibling tools such as affinity_open_document, but the 'new' scope makes the distinction reasonably clear.

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