create_custom_spread

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

Annotations are minimal (readOnlyHint=false, idempotentHint=false). The description adds that the tool draws cards, indicating a write/creation action. It does not contradict annotations. However, it does not detail side effects like session creation or storage, so its behavioral disclosure is adequate but not extensive.

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 two sentences long, both front-loaded with the action and usage guidance. Every sentence adds value without wasted words. It is concise and well-structured.

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 presence of an output schema (mentioned in context signals), the description does not need to explain return values. It covers the tool's purpose and usage context adequately for a creation tool. However, it could mention that the tool also draws cards and possibly initiates a session, but overall it is quite complete.

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 every parameter has a description in the schema. The tool description adds no additional parameter details beyond 'specific positions and meanings' which is already implied by the schema. Therefore, the description does not significantly enhance parameter understanding beyond the schema.

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 tool creates a custom spread and draws cards for it. It specifies the action verb 'Create' and the resource 'custom tarot spread', and distinguishes it from using existing spreads.

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 explicitly says when to use this tool: 'when no existing spread fits your needs'. This distinguishes it from sibling tools like list_available_spreads or recommend_spread. It implies not to use if a standard spread suffices, though it doesn't explicitly list exclusions.

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