Add Photo to Unsplash Collection

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

Annotations already declare readOnlyHint=false and destructiveHint=false. The description adds valuable context beyond the annotations: the authentication requirement, the setup command, and the fact that the target collection must belong to the authenticated user. 'Not read-only' is consistent with the annotations, with no contradiction.

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 description is two sentences, front-loaded with the action, and includes the prerequisite without excessive detail. The phrase 'Not read-only' is slightly redundant with the annotations, but it does not meaningfully hurt conciseness.

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?

Given the tool's simplicity—two required string parameters, full schema coverage, and annotations covering safety—the description is largely complete. It covers what the tool does, which collections are valid, and what the agent must do before invoking it. It does not describe duplicate-add behavior or exact return shape, but these are not essential for this operation.

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 id and photo_id are already well documented. The description adds useful semantic context by clarifying that the collection ID must reference a collection owned by the authenticated user, which also reinforces the need for OAuth.

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 uses a specific verb+resource ('Add a photo to a collection') and states the critical ownership scope ('owned by the authenticated user'). This allows an agent to distinguish it from read-only collection tools and from the sibling remove_photo_from_collection 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?

The description clearly states the prerequisite: OAuth sign-in, with the exact CLI command to run first. It does not explicitly mention when-not-to-use or name alternatives, but the add-vs-remove context and the auth requirement give sufficient situational guidance.

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