This server defines 23 tools with schemas and descriptions present, but quality is inconsistent. Most tool names follow verb_noun conventions (affinity_get_status, affinity_create_layer), which is good. However, descriptions are bilingual (English/Japanese) and often generic, many lack context about when to use the tool or what prerequisite states are required. Parameter descriptions are present but lack constraints (min/max, format guidance). Output schemas are not documented, forcing LLMs to infer response structures. Tool affinity_export_document has good enum constraints on 'format' and numeric bounds on 'quality', but most tools lack equivalent rigor. Tool affinity_send_shortcut requires users to know keyboard syntax ("^n" for Ctrl+N) with minimal guidance. Error handling is absent, no recovery guidance, no categorization of error types. The server covers a narrow domain (Affinity Designer UI automation via Windows APIs) and does not attempt composition patterns. Per-tool average is ~58, pulled down by missing output schemas, weak parameter constraints, and lack of error guidance.

• Add documented output schemas (JSON Schema format) for every tool. Document field names, types, and whether fields are guaranteed or optional. Example: affinity_get_status should define output as {success: boolean, applicationRunning: boolean, windowFocused: boolean, currentDocument: string | null, ...}
• Expand descriptions to 80-150 characters and include prerequisite context. Example: 'Create a new layer in the currently open document. A document must be open first; if none exists, call affinity_new_document.' This guides agent planning.
• Replace bilingual descriptions with English-only. Keep Japanese translations in separate documentation if needed, not in the tool definition.
• Add constraints and format guidance to parameter descriptions. For affinity_send_shortcut, specify: 'Keyboard syntax: ^=Ctrl, +=Shift, %=Alt, # = Win. Examples: "^c" (Ctrl+C), "^+s" (Ctrl+Shift+S). Use single key names (a, b, 1, 2, Return, Tab, etc.) for non-modifier keys.'
• Implement and document error responses. Example for affinity_export_document: 'If path is invalid or permission denied, return {success: false, error: "Cannot write to path: <path>", suggestion: "Verify the directory exists and you have write permissions."}'. Categorize errors as retryable (timeout, temporary lock) vs. user-fixable (invalid path, format unsupported).
• Add a dry_run parameter to destructive tools (affinity_delete_layer, affinity_close_document) to allow agents to preview side effects before committing.
• Add state query tools: get_current_document(), get_selected_layers(), get_active_layer_index(). This lets agents verify state before modifying and reduces incorrect updates.