Set Project Scratch Disk

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

Annotations declare the mutation profile (readOnly=false, destructive=false, idempotent=false), so safety is largely covered structurally. The description adds genuinely useful behavior beyond that: paths must be an existing folder or the 'SameAsProject' sentinel, and any rejected path fails the whole call (all-or-nothing semantics). It stops short of describing authorization or persistence requirements.

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 sentences, zero waste. The scope and the four targets come first, the failure semantics follow, and the atomicity constraint is placed where it matters.

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 not be explained, and annotations cover the safety profile. The description covers the atomicity and path-validation rules well; only prerequisites (open project, permission needs) and the relationship to set_scratch_disk_path are left implicit.

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 100%, so the baseline is 3; the description still adds value by defining the 'SameAsProject' sentinel and the existing-folder validation rule that the per-parameter schema strings do not mention. It does not clarify optionality (all five params are non-required) or defaults.

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 (Set) and resource (project's scratch disks), enumerates the four disk targets, and the phrase 'in one call' differentiates it from the sibling set_scratch_disk_path (singular) and get_project_scratch_disks (read). An agent can pick it 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?

Usage is implied by the enumeration of the four disk types, but the description never states when to prefer this over set_scratch_disk_path, nor any prerequisites such as a project being open. No when-not guidance is offered.

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