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

Annotations establish it is a non-read-only, non-destructive, closed-world write. The description adds meaningful context beyond that: a required auth token (NOMADSTAYS_MCP_AGENT_TOKEN) and the fact that the full gallery set must be supplied. It does not say what happens if the set does not match, but the added auth and ordering semantics are substantive.

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?

Three short clauses, front-loaded with the action, then the key constraint, then the auth requirement. Every sentence carries information an agent needs; nothing is padding.

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 four-parameter mutation with no output schema and full schema coverage, the description covers the prerequisite lookup, the ordering constraint, and the auth gate. The only gap is error behavior when fileNames does not match the current set.

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 baseline is 3; fileNames and roomArea are already fully documented in the schema. The description reinforces the 'FULL current gallery' meaning of fileNames, but adds no new format or syntax details for stayId/roomId/roomArea.

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 ('Change the display order of a room's photo gallery'), which is enough to tell it apart from reorderStayPhotos at the gallery level. It does not explicitly name the stay-level sibling or contrast the two scopes, so sibling differentiation is implied rather than stated.

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?

Gives a concrete prerequisite ('call getMyStayRooms first') and an operational constraint (fileNames must be the FULL current gallery, same set, just reordered) that effectively rules out add/remove use cases. No explicit when-not guidance against deleteRoomPhoto or uploadStayPhoto, but the context is clear.

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