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

With no annotations, the description carries the burden and it delivers: it discloses a failure condition (roster full) and a prerequisite (May plan + header). It doesn't mention return values or idempotency, but it covers key side effects and constraints well for a simple create operation.

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?

Four sentences, no fluff. The core action is front-loaded, and the subsequent sentences add valuable context (workspace contents, plan limits, header requirement). It is concise without omitting important operational details.

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 tool with a single parameter and no output schema, the description covers the essential context: purpose, what the workspace contains, failure mode, and prerequisites. It could mention the return value, but that is minor given the tool's simplicity.

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% and the schema fully describes the 'name' parameter. The description adds no additional parameter meaning beyond the schema, so the baseline of 3 is appropriate.

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 clearly states the action ('Add a client workspace'), the resource, and what it contains ('brand's profile, runs, creatives and campaigns'). This differentiates it from sibling tools like create_order or draft_brand_from_website, making the purpose unambiguous.

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?

Provides strong context for usage: prerequisites ('Needs the May plan and an X-Mako-Key header') and a failure condition ('fails when the roster is full'). It does not explicitly name alternatives or state when NOT to use it, but the context is clear enough that an agent can infer when this tool is appropriate.

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