list_modular_parts

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered without description help. The description adds only the workflow linkage to weapon_build; it says nothing about result shape (e.g., grouping by part slot or per-kind fields) that would exceed the annotations.

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?

A single compact sentence with the action, the resource, the parameter scope, and the downstream consumer all front-loaded. No filler and nothing wasteful.

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 one-parameter read-only lookup with no output schema, the description covers what the tool returns (parts) and why (to feed weapon_build). A little more on how results are organized per kind would make it fully complete, but nothing essential for correct invocation is missing.

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?

There is one parameter, kind, whose enum values (zaw, kitgun) are already self-documenting in the schema; the description echoes both by name, confirming that Zaw and Kitgun are the supported part categories. That is adequate meaning for a single enum parameter even at 0% schema description coverage.

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 (List) and a specific resource (parts for building a Zaw or Kitgun), so an agent can tell it apart from sibling builders like weapon_build. It does not explicitly contrast with list_weapons or search_mods, but the noun scope is narrow enough to be unambiguous.

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 'with weapon_build' implies this is a prerequisite lookup step before calling weapon_build, which is useful implied workflow. However, there is no explicit when-to-use/when-not statement, no mention of whether it is required before weapon_build, and no exclusion of other part-related paths.

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