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

Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint false), the description discloses the interaction flow (card with example images, user picks effect/layout/caption), the delivery channel (new browser tab), privacy ('photos stay on the device', 'no signup, no app'), and a hard limitation ('The booth cannot take photos inside the chat'). That is exactly the behavioral context annotations cannot carry.

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 use case is front-loaded and each sentence carries distinct information (trigger, flow, privacy, limitation, exclusion). It is on the long side for a 5-parameter tool, but no sentence is redundant.

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 values need no explanation, and annotations cover the safety profile. With usage triggers, flow, privacy and exclusions all present, an agent has everything needed to invoke 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?

Schema coverage is 100% and three parameters are enums, so the schema already documents meaning, defaults and allowed values. The description frames the selection flow and hints that occasion only drives effect suggestions, but adds no syntax or format detail beyond the schema; baseline 3 applies.

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 names a specific resource (photo booth / Fotobox) and the concrete action (shows an effect-picker card, then opens the booth in a browser tab with the chosen settings). It explicitly distinguishes itself from the sibling collect_guest_photos_info, so an agent can route correctly without opening any schema.

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 states when to use it (user wants a photo booth or fun group photos with effects at an event) and gives explicit exclusions: 'Do not use for editing existing photos or for collecting photos from guests (use collect_guest_photos_info for that)'. The named alternative and the boundary condition leave nothing to inference.

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