create-album

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It explicitly states this is a WRITE tool, requires APPLE_PHOTOS_MCP_ENABLE_WRITES=1, launches Photos.app, requires macOS Automation permission, and writes to the currently open library. It also clarifies that it only creates albums/folders and never deletes/moves/modifies photos. This goes well beyond what structured annotations would provide and fully discloses side effects and prerequisites.

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 well-structured with clear labeled sections: 'Use when', 'Returns', 'Do not use when', and 'Safety'. It front-loads the primary purpose and conditions, then covers return semantics and safety. Every sentence serves a purpose: providing usage context, return behavior, alternatives, or safety/prerequisites. Despite length, it is efficient and easy to parse for an agent.

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 tool with side effects, permissions, and environmental dependencies, the description is exceptionally complete. It covers purpose, usage scenarios, return value semantics, idempotency, safety restrictions, environment variable requirement, automation permission, and library targeting. The output schema is present (as per context signals), so return format is already documented. Nothing critical is missing for an agent to call this tool 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?

Although schema coverage is 100% (both name and folder have descriptions), the description adds meaningful context: it explains folder path syntax (e.g., 'Trips/2026'), that folders are created as needed, and the idempotent matching behavior ('without folder the name is matched anywhere in the library, with folder only inside that folder'). It also explains the 'created' return flag and its semantics. This adds value beyond the schema's basic 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 opens with a precise statement: 'you need an album to file photos into — a new album by name, optionally nested inside a folder path'. It specifies the verb (create), resource (album), and gives concrete examples like quarantine album or per-trip album. It also differentiates from siblings by explicitly naming list-albums and add-to-album as alternatives, so an agent can clearly distinguish this tool from related ones.

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 includes a 'Use when' section that provides concrete scenarios and a 'Do not use when' section that names the correct sibling tools (list-albums for listing, add-to-album for adding photos). It also explains idempotency and the behavior when the album already exists, which helps the agent decide when to call this tool versus alternatives. This is explicit and thorough.

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