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

Annotations only declare readOnlyHint=false, openWorldHint=false, destructiveHint=false, which is thin for a create operation. The description adds two genuinely useful facts beyond them: the call consumes the workspace's field quota, and it may return a needs_confirmation envelope requiring the agent to pause and get user approval.

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 short front-loaded sentences: what it creates, its cost, and the confirmation-flow obligation. No filler, and the most consequential operational facts (quota, approval) are stated plainly rather than buried.

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?

There is no output schema, so the description must carry return behavior, and it does flag the needs_confirmation case; quota consumption is also disclosed. It stops short of describing the success payload (e.g. returned field id), which would fully close the loop for a create tool.

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% with five well-described parameters, including enum values and the workspace-token caveat, so the schema carries the load. The description only re-characterizes originIdea ('the seed') and adds no parameter-level detail beyond what the schema already states, so baseline 3 applies.

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 gives a specific verb and resource ('Creates a field') and defines the domain concept ('the seed of an exploration canvas'), so an agent knows this instantiates a Prism field rather than mutating an existing one. It does not explicitly name the sibling it differs from (prism_fields_update/get/delete), but the create semantics are 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?

Usage is implied by the name and the confirmation note, but there is no explicit when-to-use/when-not guidance or routing to alternatives such as prism_fields_update or prism_panels_create. The 'wait for approval' instruction is useful process guidance, not selection guidance.

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