Set default farm

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

Annotations establish non-readOnly, idempotent, non-destructive, and the description adds genuinely useful context by clarifying that the effect is on session context rather than farm data. It stops short of stating whether the setting persists across sessions or what confirmation is returned, so it is strong but not exhaustive.

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?

One sentence front-loads the effect, then immediately qualifies scope and prerequisites. Every clause earns its place with no 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 one-parameter session-state setter with no output schema, the description covers effect, scope, and usage conditions completely. Nothing an agent needs in order to call it correctly is missing.

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 the single farm_id parameter is fully documented as a UUID in the schema, so the description is not required to compensate. It adds no syntax or meaning beyond what the schema already provides, making the baseline 3 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?

States a specific verb and resource ('Change the saved default farm') and scopes it precisely to 'later calls on this session', which separates it from farm-data tools like get_farm, list_my_farms or get_current_context. An agent can tell what this mutates without opening the 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 gives both a when-not condition ('unnecessary when every scoped call passes farm_id explicitly') and a when condition ('should be used only when the user asks'). This is exactly the routing guidance an agent needs to avoid gratuitously changing session state.

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