Create a zone

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

The description discloses status is always active on create and notes the dry-run default, which adds value beyond annotations (readOnlyHint=false, destructiveHint=false). It also warns about plan limit errors. No contradictions with annotations.

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?

Three sentences pack all essential information without redundancy. Each sentence serves a purpose: purpose, options, and behavior. Front-loaded with the core action.

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?

The description covers creation behavior and dry-run, but since no output schema exists, it does not explain return values or error structure beyond the 402 limit. For a mutation tool, this leaves some ambiguity about what the agent can expect back.

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%, but the description adds key context: postback_url should include {source_click_id}, user_email is for publisher owner, and confirm controls dry-run. This enhances understanding beyond schema descriptions.

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 explicitly states 'Create a traffic-source zone in the current namespace,' with a specific verb (create) and resource (zone). It clearly distinguishes from sibling tools like update_zone and cut_zones. The scope ('current namespace') adds precision.

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 details required parameters (name) and optional ones, explains the dry-run default and confirm flag, and mentions plan limit and error code (402). It provides context for when to use this tool vs alternatives (e.g., update_zone, cut_zones), though it does not explicitly state 'use when creating a new zone only'.

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