update_service

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

With no annotations, the description carries the full burden and does disclose two real behavioral traits: the update is a JSON merge patch (partial, unspecified fields preserved rather than replaced) and changes do not take effect until a redeploy. It omits permissions/authorization requirements and whether the change is reversible, which keeps it from a 5.

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?

Two short sentences with zero filler; the core action is front-loaded and the operational caveat follows immediately. Nothing is repeated from the schema or wasted.

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 mutation tool with no annotations, no output schema, and an opaque nested `spec` object, the description covers the merge semantics and the redeploy requirement but leaves the agent guessing about valid spec fields and the response shape. Adequate but with clear gaps.

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 50%: the `service` parameter is documented in the schema ('Service id or `project.service`'), but `spec` is an untyped nested object with no field-level documentation. The description adds real meaning by saying the spec is a JSON merge patch, implying partial specs are acceptable, but it never says which spec fields are valid or required.

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 ('Change') and resource ('a service's settings') plus the mechanism ('JSON merge patch of its spec'), which clearly separates it from create_service and delete_service in the sibling list. It stops short of naming the siblings it is distinguished from, so it lands at 4 rather than 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?

'Redeploy to apply' gives a useful follow-up cue pointing toward the deploy/restart siblings, and 'Change a service's settings' implies the mutation use case. There is no explicit when-not guidance (e.g., use create_service to create, delete_service to remove) and no prerequisites, so usage is only implied.

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