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

Annotations mark it as non-readOnly and non-destructive, and the description adds real behavioral context beyond that: partial-update semantics ('only pass the fields you're changing'), the 409 failure mode for submitted applications, and the required NOMADSTAYS_MCP_AGENT_TOKEN. It does not describe the response shape, but for a mutation tool this is solid disclosure.

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 tight sentences, front-loaded with the core action, then the partial-update rule, then the failure/auth caveats. Every sentence adds distinct, necessary information with no waste.

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?

With no output schema and 20% schema coverage on 25 parameters, the description covers the important behaviors (partial update, 409, auth) but leaves field-level semantics largely unexplained. It is adequate for the mutation workflow but not complete given the schema gap.

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 only 20% across 25 parameters, so the description must carry the burden of explaining the fields — and it does not. The only param-level meaning it adds is the partial-update rule and a deferral to createStayApplication ('same field set and validation rules'), leaving the meaning of most fields undocumented in either place.

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+resource with scope: 'Update any subset of fields on an existing, not-yet-submitted Stay Application.' It explicitly distinguishes itself from createStayApplication and implicitly from submitStayApplication by spelling out the update/partial semantics. An agent can tell it apart from siblings without opening a 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?

Gives clear conditions: the application must already exist and be not-yet-submitted, and it fails with 409 if already submitted, so the when-not case is stated. It also points to createStayApplication for the field set. No explicit direction on choosing against other update-style siblings, 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.