sezzle_validate_session_payload

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the description's job is lighter. It adds valuable behavioral context: 'deterministically' reinforces idempotency, and 'without sending customer or order data' discloses that the tool performs no network I/O. This goes beyond what annotations provide, though it does not explain return format or error behavior.

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 a single, concise sentence that front-loads the primary action and then adds two key qualifiers. Every word earns its place; there is no redundancy or fluff.

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 simple one-parameter tool, the description is adequate but incomplete. It does not state what 'validate' returns (e.g., a boolean, a list of errors) or what constitutes a valid payload. Since there is no output schema, the description should clarify the outcome of the validation to fully prepare the agent.

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?

The input schema has only one parameter with zero description coverage, so the description must compensate. It only refers to 'proposed Sezzle session payload' without explaining the expected structure, required fields, or format. The description adds no meaning beyond the parameter name itself.

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 a specific verb ('Validate') and resource ('proposed Sezzle session payload'), and distinguishes this from sibling tools like sezzle_validate_redirect_urls by specifying that it validates the session payload specifically. It also adds a distinguishing qualifier ('deterministically without sending data') that separates it from a general validation call.

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 phrase 'without sending customer or order data to Sezzle' implicitly tells the agent when to use this tool: when a local, deterministic validation is needed before any external API call. It does not explicitly name alternatives or exclusions, but the context is clear enough to guide selection among siblings.

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