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

Annotations declare non-read-only, non-idempotent, non-destructive, closed-world, but don't explain the session model. The description fills that gap by disclosing that a session_id and the first step's options are returned, and that the id must be threaded into bom_submit_input. It omits auth/permission requirements, keeping it short of a 5.

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, each load-bearing: what it does, what it returns, and the prerequisite tool. No repetition of the name or title.

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?

No output schema exists, yet the description compensates by naming the return payload (session_id plus first-step options). Combined with the 100%-covered single-param schema and clear sibling routing, an agent has everything needed to call this correctly.

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% and the single parameter is documented with concrete example IDs, so the schema already carries the semantics. The description adds no format or constraint detail beyond it; 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?

States a specific verb+resource+scope: 'Begin a new BOM building session for a specific use case.' This is clearly distinguishable from bom_list_use_cases (enumeration) and bom_submit_input (advancing a session).

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?

Explicitly instructs 'Use bom_list_use_cases first to see available use case IDs' and names bom_submit_input as the follow-on tool, establishing the workflow ordering. It doesn't state a when-not-to-use condition, but for a step-0 tool this covers the practical selection need.

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