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

The annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the description does not need to restate safety. It adds value by detailing what the canonical record contains—provenance, vendors, datasheet links—which lets the agent anticipate the response shape. It doesn't mention the privacy-logging behavior of project_context, but that is disclosed in the parameter schema, so no contradiction exists.

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 a single dense sentence that front-loads the core purpose ('complete canonical record for one part') and then efficiently enumerates the key record components. Every phrase earns its place without any filler or repetition of the 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?

With an output schema present, the description need not detail return fields; it instead gives the high-level data categories. Combined with the annotations (read-only, idempotent) and full schema coverage, this is adequate for a two-parameter get-by-id tool and leaves no critical gaps.

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%: both id and project_context have clear descriptions, including an example for id and a note about anonymous logging for project_context. The tool description adds no extra parameter-specific meaning, so it meets the baseline of 3 but does not exceed it.

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 starts with 'The complete canonical record for one part,' clearly establishing a get-one-part-by-id action with a specific resource. It enumerates the record's contents (attributes with provenance, vendor prices, datasheet links), which distinguishes it from siblings like search_parts or compare_parts.

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 'complete canonical record for one part' clearly implies using this when you have a known part id and need the full record, and the sibling tools (search_parts, compare_parts) set the context for alternatives. However, it never explicitly says 'use this when...' or names a specific alternative, so it falls just short of full explicit guidance.

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