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

Adds substantial behavior beyond the readOnly/openWorld annotations: provenance lines with licensing terms (own-forge files reusable, keep provenance on library copies, never copy 'reference only' files), a prompt-injection warning to treat library source as data, and the non-obvious rule that an excluding switch refuses the call rather than returning a plain not-found.

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?

Front-loads the core action before the caveats, and every sentence carries distinct information (paths override, provenance/licensing, injection warning, forgeId). It is dense and em-dash heavy, but nothing reads as 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?

With no output schema, the description still explains the return ('file manifest plus the entrypoint; each manifest entry carries exports and summary'), and it covers licensing, safety, and the forgeId scoping behavior. Nothing an agent needs to invoke it correctly appears 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?

Schema description coverage is only 33% (forgeId alone is documented), so the description compensates by defining id (a search_reference_parts hit), paths (file paths whose exports you want, capped at 10), and forgeId's switch-sensitive semantics. It adds real meaning, though it doesn't describe the id's format or edge cases.

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 and resource ('Read the source of one part ... by id') and explicitly scopes it to a search_reference_parts hit, which separates it from the sibling search_reference_parts (which finds hits) and read_part_files. An agent can identify the tool's role without opening the schema.

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?

Gives clear operational guidance: ids come from search_reference_parts, and callers should pass paths (up to 10) naming files whose exports they want 'instead of reading the entrypoint blind,' plus how to use forgeId. It stops short of an explicit when-not-to-use or a direct comparison against read_part_files.

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