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

The annotations only provide flags (readOnlyHint: false, destructiveHint: false), so the description carries the transparency burden. It reveals that a GVC without placement cannot run workloads, that locationOptions is only geo-routing tuning and not placement, and that server-side resolution of location names occurs. It also warns against guessing regions. It doesn't detail side effects like cost or irreversible changes, but the immutability of names is covered in the schema. Overall, it adds meaningful behavioral context without contradiction.

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?

The description is detailed but every sentence earns its place. It is front-loaded with the core purpose and placement requirement, then covers the domain separation and ask-first guidance. It is concise for the complexity of the tool, using clear, direct language without redundancy. The structure flows logically from purpose to key constraints.

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?

Given the tool's complexity (15 parameters, nested objects, output schema exists), the description covers the most critical aspects: placement is required, what to do if not specified, and what is not handled here (domains). It also references the alternative tool (list_resources) for user choices. The presence of an output schema means return values need not be explained in the description. The description is adequate for an agent to invoke this tool correctly in most scenarios.

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%, so the baseline is 3. The description adds semantic value beyond the schema by clarifying the interaction between `locations`, `locationQuery`, and `locationOptions`, and by explicitly stating that `locationOptions` is not placement. It also gives usage context for the `locations` parameter (e.g., 'never pick one silently'). This helps the agent understand parameter relationships and constraints beyond what individual descriptions provide.

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 uses a specific verb ('Create') and resource ('GVC') and clearly defines what a GVC is: 'the deployment scope workloads live in.' It also explicitly differentiates from sibling tools by stating that custom domains are configured via create_domain, not on the GVC, and the placement guidance distinguishes it from other create tools.

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?

The description gives explicit when-to-use and when-not-to-use guidance. It states that placement is configured through `locations` or `locationQuery`, and that `locationOptions` is not placement. It instructs the agent to ASK first if placement is not specified, referencing list_resources kind='location' as the alternative, and explicitly says 'never guess a region and never create an empty GVC.' It also notes that custom domains are handled by create_domain, not this tool.

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