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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely new information about composition — that the response bundles the record's gaps note and all capacity statements scoped to it — but says nothing about missing-id behavior or response shape.

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?

One compact sentence with the scope front-loaded ('One fab site in full'), which is good. But the qualifying clauses are wordy and convoluted, costing clarity without adding proportional value.

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 does sketch the return contents (record, gaps note, capacity statements), which is the right instinct. It still leaves the id format and not-found behavior unspecified for a single-parameter lookup tool.

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 required parameter, 'id', with 0% schema description coverage, so the description carries the burden and does not meet it: it never states that the id identifies a fab, nor what form the identifier takes. The single implicit mapping to 'one fab site' is the only compensation.

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?

It conveys that the tool returns one fab site's full record, plus its gaps note and covering capacity statements. But the phrasing ('the note that says what this record does not know about it', 'every capacity statement whose sentence covers it') is opaque domain jargon, and the description never names the sibling it differs from (find_fabs, record_overview).

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?

No explicit when-to-use guidance and no exclusions. An agent must infer that this is the detail view for a single fab versus find_fabs for discovery or record_overview for a summary; the description never makes that routing explicit.

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