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

Annotations already carry destructiveHint=true and readOnlyHint=false, so the safety profile is known; the description goes further by spelling out the specific loss ('WITHOUT saving it') and prescribing a data-preserving workaround. It stops short of stating irreversibility/undo availability, so it is strong rather than complete.

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 short sentences, front-loaded with the destructive consequence before the recommended alternative. Every clause earns its place, including the parenthetical about psd preserving layers.

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?

Covers the destructive nature, the alternative route, and the format nuance; return values are handled by the existing output schema. What remains unstated is failure behavior (e.g., invalid or already-closed image id), a minor gap for a single-param 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?

Only one parameter and schema coverage is 100%, with the schema itself explaining 'Image id, as returned by open_photo'. The description adds no additional meaning about the identifier, which is the expected baseline when the schema does the work.

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 ('close a photo') and immediately qualifies the scope with 'WITHOUT saving it', which is the key differentiator. It also names the sibling that handles the opposite need (export_photo), so an agent can route without opening either 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?

Explicitly says when to reach for another tool: 'If the work should be kept, export it first with export_photo'. That is a concrete alternative plus the condition that selects it, and it even names the format (psd) that preserves layers.

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