photos list app media items

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

Annotations already declare readOnly, idempotent, non-destructive, open-world, so the safety profile is covered. The description adds genuinely non-obvious behavior: baseUrl values expire after about 60 minutes, which tells the agent results are time-limited and must be consumed promptly. It stops short of describing pagination behavior or result ordering.

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 tight sentences, no filler, with the core listing scope front-loaded and the expiry caveat placed where it is read before acting. Nothing is redundant with the title or schema.

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?

An output schema exists, so return-value explanation is not required, and the expiration note is a real asset. However, with zero schema prose and no pagination semantics for page_size/page_token, an agent cannot reliably page through a large result set — a meaningful gap for a list tool.

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 description coverage is 0%, so all three parameters rest on the description. album_id is partially explained ('one app-created album'), but page_size (default 25) and page_token receive no explanation at all — no max page size, no pagination loop guidance — leaving the primary iteration mechanism opaque.

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 and resource ('List media items') plus a meaningful scope restriction ('uploaded by this app'), which distinguishes it from the sibling that lists picked media. It does not explicitly name photos_list_picked_media_items or photos_list_app_albums, so an agent must infer the boundary.

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?

'optionally only those in one app-created album' implies when to pass album_id, giving some conditional guidance. But there is no statement of when to prefer this over photos_list_picked_media_items, nor any guidance on iterating pages with page_token.

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