add-to-album

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

With no annotations, the description carries full responsibility and does so thoroughly: it discloses the write nature, the environment variable gate, that photos are never modified/deleted, idempotency, AppleScript launching behavior, Automation permission requirement, and the target library. It even lists error conditions.

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 longer than average but every sentence adds value. It is front-loaded with 'Use when', then returns, exclusions, and safety. The structure with labeled paragraphs makes it scannable and informative without redundancy.

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 write tool with no annotations, this is complete: it covers prerequisites, return values, failure modes, constraints, side effects, and permissions. The output schema exists, and the description augments it with concrete examples and edge-case handling.

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 100%, so the baseline is 3. The description adds meaningful context beyond the schema: where UUIDs come from (query/find-duplicates), the idempotent add behavior, and the album existence requirement. It doesn't fully explain the output mapping but parameters are well contextualized.

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 clearly states the tool adds photo UUIDs to an album, with concrete examples ('collecting duplicate extras into a quarantine album'). It explicitly distinguishes from siblings by naming remove-from-album for the inverse operation and create-album for missing albums.

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 provides explicit 'Use when' conditions (having photo UUIDs from query/find-duplicates) and explicit 'Do not use when' exclusions (album doesn't exist — use create-album first; wanting photos out — use remove-from-album). This is exactly the guidance an agent needs for tool selection.

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