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

With readOnlyHint=false, destructiveHint=false and openWorldHint=false already declaring the safety profile, the description usefully adds that it is a partial update ("Only fields supplied are changed") and that an account-scoped agent token is required. That is genuine behavioral context beyond the annotations, though nothing is said about failure modes or what happens to the stay record on success.

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 sentences, zero filler, with the action and its field scope front-loaded ahead of the precondition and the partial-update note.

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 low-risk partial mutation with full annotation coverage and a fully documented 3-parameter schema, the description supplies the missing auth requirement and update semantics. Only edge-case behavior (validation errors, what the response contains) is absent, and no output schema exists to cover 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?

Schema description coverage is 100% and both editable fields are already labeled OPTIONAL, so the schema carries the load. The description's "only fields supplied are changed" reinforces the optionality but adds no format, length or validation detail beyond the schema.

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 (Update) and resource (a Stay's title and/or description), and the field scope crisply separates it from siblings like updateStayContacts, updateStayFacilities, updateStayPackage and updateStayRoom. It does not name any sibling explicitly, so the differentiation is inferred from the field list 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 real precondition — an MCP agent token scoped to the owning account — which tells the agent when the call will succeed. However, it never says when to reach for this tool versus the other updateStay* siblings, nor when not to use it, so the routing guidance is only implied.

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