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

Annotations only indicate readOnlyHint=false and destructiveHint=false, so the description adds valuable behavioral context: it must be called after getMyStayRooms, the fileNames must exactly match the current set, and it requires a specific token. This goes beyond the schema and annotations.

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 purpose and immediately giving critical constraints. Every sentence adds value without redundancy or filler.

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 mutation tool with four parameters and no output schema, the description provides all necessary context: prerequisite workflow, required token, and the critical fileNames constraint. It is complete for an agent to invoke the 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?

The input schema covers all four parameters with descriptions, achieving 100% coverage. The description reinforces the fileNames constraint but does not add significantly new parameter meaning beyond what is already in the schema. Baseline 3 is appropriate.

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 clearly states the action: 'Change the display order of a room's photo gallery.' It specifies the resource (room's photo gallery) and the operation (reorder), which distinguishes it from sibling tools like deleteRoomPhoto or reorderStayPhotos.

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 gives explicit usage context by requiring 'fileNames must be the FULL current gallery' and instructs to 'call getMyStayRooms first.' This provides a clear precondition, though it does not explicitly name alternatives like reorderStayPhotos for comparison.

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