Create a buckslip

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

The description reveals key behavioral traits beyond annotations: the requirement for a publicly-reachable PDF URL or base64 data URI for 'front', the multipart/form-data encoding (important for HTTP handling), and inventory reservation behavior. These details are not covered by annotations (idempotentHint, openWorldHint) and add significant value for correct invocation.

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 extremely concise: three sentences that each serve a purpose. It defines the object in the first sentence, specifies the front parameter format in the second, and clarifies the API encoding in the third. No redundancy or filler.

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 create tool with 6 parameters and no output schema, the description covers the most critical aspects (front format, multipart encoding, inventory behavior). It does not detail every parameter, but the schema already provides descriptions for most. Some information about the response or error conditions could enhance completeness, but it is adequate for an 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?

With 83% schema description coverage, the baseline is 3. The description adds meaning by specifying that 'front' must be a PDF URL or base64 data URI, and notes the multipart encoding (which relates to how parameters are sent). This improves understanding beyond the 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 clearly states the verb 'Upload' and the resource 'buckslip', defining it as an 8.75"x3.75" promotional insert for letters. This distinguishes it from sibling tools like lob_cards_create or lob_letters_create, as it specifies the exact resource type.

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 implicitly indicates when to use this tool (to create a buckslip) and provides context about inventory reservation and multipart requirement. However, it does not explicitly state when not to use it or provide alternatives, but the context is clear enough for an agent to decide.

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