amend_assignment

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

With no annotations, the description carries the full burden and does well: partial-update semantics, explicit clear operations (target={} clears the target, review={} clears the triggers), note persistence in history, the returned 'previous' values, and a cost hint ('One game read'). It omits error/auth behavior and any failure modes, keeping it short of 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?

Front-loaded with the core in-place/partial semantics, then the usage cases, then the return and cost. It is appropriately sized, though the parenthetical clarifications are dense and the 'review as in assign' clause reads awkwardly.

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 9-parameter mutation tool with no annotations and no output schema, the description covers most fields, the clearing rules, the return value with `previous`, and the cost. Gaps remain around assignment_id semantics and error/edge behavior, but an agent has enough to invoke it correctly.

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 0% and there are 9 parameters, so the description must compensate — and it does, defining role, purpose, done_when, review, note, and the replace-vs-clear semantics of unit_ids/city_ids/target beyond anything the bare schema conveys. The replacement/list-overwrite rule is exactly the kind of meaning the schema lacks.

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 an active assignment in place' — and nails the scope with 'only the fields given change'. It implies the create/close counterparts (assign, close_assignment) by referencing 'as in assign', so 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 concrete trigger conditions: 'Use it when a unit was upgraded (new id), a site moved, or the review turn passed and the plan still holds.' That is a clear when-to-use, and the 'as in assign' reference implies the create alternative, but there is no explicit when-not or named-alternative routing.

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