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

With no annotations to provide safety/behavior hints, the description takes on the full burden. It discloses the background generation process, quality gates, and ~5-minute publication timeframe. This goes beyond the schema by describing the tool's internal behavior and outcome, though it doesn't mention failure modes or response structure.

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 dense but well-organized. Each sentence contributes meaning: purpose, process, family parameter mapping, and usage directive. It uses compact lists and abbreviations (e.g., 'pin_header_254 (2.54mm)') to avoid repetition. While longer than typical, the complexity of the tool justifies the length.

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 tool with 3 parameters, no output schema, and no annotations, this description is remarkably complete. It covers purpose, behavior, parameter usage, family options, timing, and which siblings to try first. The agent has enough information to decide when and how to invoke the tool 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?

The schema covers 67% of parameters, but the description adds substantial semantics: it maps family enums to specific parameters, provides pin count ranges (1-40), and lists exact variant codes for each family (e.g., ht73xx values). This helps the agent select valid parameter combinations far beyond the schema's generic 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 tool's purpose: 'Request on-demand generation of a parametric part that isn't in the registry yet.' This specific verb+resource combination distinguishes it from sibling tools like get_part and search_parts, reinforced by the closing directive 'Always try get_part / search_parts first.'

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?

Explicit guidance is provided: 'Always try get_part / search_parts first' tells the agent when NOT to use this tool. It also details family-specific usage, indicating which parameter ('pins' vs 'variant') applies to each family, making when-to-use highly clear.

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