set_location

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

With no annotations, the description must carry the behavioral load, and it does disclose meaningful side effects: cooperative, warehouse and price context all change, and a signed-in user's fulfilment selection is overridden. It is silent on scope and persistence (does the override last for the session, the account, or one request?), on whether the postcode is validated, and on what happens for a non-Swiss or malformed input. Useful but incomplete for a state-mutating tool.

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, front-loaded with the effect and then the default-behavior rationale; there is no filler. The only weakness is that the second paragraph's purpose (contrasting guests vs. signed-in users) could be tightened into one clause.

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?

An output schema exists, so return values need no explanation, and the description covers the main effects and the defaults it overrides. For a mutation with no annotations, however, the missing persistence scope and input validation leave a real gap an agent would want filled before calling 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 0% for the single required zip_code property, so the description must supply the meaning, and it does add the key constraint that the postcode is Swiss. It says nothing about format (four digits, leading zeros), validation, or error behavior for invalid codes. Some value added, but not enough to fully compensate for the empty schema documentation.

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 states a concrete action on a concrete resource: it makes shopping behave as if the user were located at a given Swiss postcode, and enumerates the three things that change (cooperative, warehouse, prices). That is far more informative than the bare name 'set_location'. It does not explicitly differentiate itself from siblings like fulfilment_selection, my_fulfilment_selection, or my_location, so it stops short of a 5.

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?

It gives real decision context: guests otherwise get a backend-guessed location, and signed-in users otherwise fall back to their own fulfilment selection, which this call overrides. That tells an agent when the tool is needed and what it replaces. It never names an alternative tool to use instead, so it lacks explicit exclusions.

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