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

The annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered structurally. The description adds the one thing the annotations cannot: that the call returns every effect with a short description, useful because no output schema is defined. It does not mention ordering or whether the list can be filtered by category.

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, zero padding, and the ordering is correct: the trigger condition is front-loaded, then the return shape. Nothing is repeated from the title or annotations.

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 parameterless, read-only enumeration tool with full annotation coverage and only one optional enum parameter, the description supplies everything needed: when to call it and that it returns all effects with descriptions. No output schema means nothing further is expected of it.

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?

There is a single optional parameter (language) and schema description coverage is 100%, including the enum values and the guidance to match the conversation language. The description adds no parameter-level information, so the baseline of 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 the exact resource (effects/filters/frames of the online photo booth) and grounds it in concrete examples (big head, meme, Halloween, wanted poster), which cannot be confused with the sibling tools open_photo_booth or collect_guest_photos_info. An agent can identify the tool without opening the 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 gives an explicit trigger condition: 'Use this when the user asks which effects, filters or frames the online photo booth has.' That is a clear when-to-use statement, but it names no alternatives or exclusions (e.g. what to use when the user wants to apply an effect rather than enumerate them).

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