photos list picked media items

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

Annotations already cover readOnly, idempotent, and openWorld, so the bar is lower. The description nonetheless adds real behavioral context: the returned baseUrl requires the same OAuth token and expires after roughly 60 minutes, which is a non-obvious operational constraint.

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 sentences, front-loaded with the core action, and no wasted words. The second sentence is slightly cryptic but earns its place by carrying the auth and expiry warning.

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 shape needn't be explained. Still, with 3 entirely undocumented parameters, no pagination guidance, and no explicit prerequisite to create a picker session, the definition leaves gaps an agent would need to close.

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 0% across 3 parameters. The description alludes to a session (implying session_id) but says nothing about page_size or page_token semantics, defaults, or pagination behavior, so the agent must infer pagination from the schema alone.

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 the items the user picked in a Picker session.' That distinguishes it reasonably from photos_list_app_media_items and photos_list_app_albums by scope, though it never explicitly contrasts with those siblings.

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?

Usage is implied by the 'Picker session' framing and the 60-minute expiry note, which hints at a time-bound workflow. However, it never explicitly says to call photos_create_picker_session first or when to prefer this over the app-media listing siblings.

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