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

Annotations already mark the tool as read-only, idempotent, and non-destructive, so the bar is lower. The description adds useful behavior beyond those hints: it does not perform verification itself, it flags unrecognized lab names, and it explains what 'FGAA' means.

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 front-loads the main purpose and ends with a crisp boundary statement. The enumerated lab list is useful but makes the first sentence denser than necessary; still, each sentence earns its place.

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 and read-only annotations present, the description does not need to explain return values or safety. It covers the routing behavior, no-verification caveat, lab coverage, and unrecognized-lab handling, but the unexplained report_number parameter is a notable completeness gap.

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 documents 'lab' but leaves 'report_number' completely undescribed, and the description never explains how report_number is used or whether it is needed for the verification page or checklist. The list of lab names adds some context for the 'lab' parameter, but it does not compensate for the missing report_number semantics.

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 states a specific action: return the issuing laboratory's verification page plus a four-step checklist for confirming a grading report. It also explicitly clarifies that the tool routes to the lab and does not verify the report itself, which clearly separates it from siblings like verify_gem_passport.

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 description gives clear context on scope — it covers named labs including coloured-stone laboratories and flags unrecognized lab names. The final sentence, 'Routes to the lab; does not verify the report itself,' is an effective when-not-to-use boundary, though it does not explicitly name sibling alternatives.

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