Photos: Download

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

Annotations declare destructiveHint=true, and the description usefully narrows that: writes are confined to allowed local folders and existing files are preserved unless overwrite=true. That scoping context goes beyond the annotations. It doesn't cover failure modes for missing IDs or partial batches, which would be the next layer.

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?

Three tight sentences, front-loaded with verb, resource, and destination, then behavior, then the sibling escape hatch. No filler.

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?

With no output schema, the description adequately characterizes the result (one file per item, named after the original, previews suffixed). It stops short of describing return values or progress reporting, but nothing essential for correct invocation is missing.

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 the naming convention ('one file per item, named after the original') that the schema does not state, and reinforces the overwrite-skip semantics. The size and space parameters' meanings are left entirely to the schema.

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?

States a specific verb (download) and resource (Synology Photos items by id) plus the destination (a local folder) and the output form (original files or JPEG previews, one file per item, named after the original). It also explicitly distinguishes itself from download_file in a sibling module.

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?

Gives an explicit alternative route — use File Station's download_file for files outside Photos when that module is enabled — which is a clear when-to-use rule. It doesn't address when to prefer copy_photos or when to pick previews over originals in prose, but the core routing guidance is present.

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