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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), and the description adds genuinely new behavior: substring, case-insensitive name matching and code-prefix matching. It stops short of disclosing result ordering, whether partial matches are ranked, or what happens on zero matches.

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?

Four short lines, front-loaded with the purpose before the kind enumeration and matching rules. The kind list duplicates the enum from the schema, which is minor redundancy but aids at-a-glance scanning.

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 simple read-only lookup with full schema documentation and no output schema, the description covers purpose, entity kinds, and matching semantics well enough to call correctly. It omits what a returned row contains (code plus official name pairing) and any ordering, which is a small gap rather than a blocker.

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 coverage is 100%, so the baseline is 3, but the description adds meaning beyond the schema by specifying prefix matching for codes and case-insensitive substring matching for names, which the schema only gestures at with 'Words in the name, or the code itself.' It adds nothing about limit, though that is fully documented in the schema.

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 ('look up codes and official names') and enumerates the seven kinds of entities covered, so an agent knows exactly what domain this resolves. It does not distinguish itself from the sibling browse_codes or naics_finder, leaving ambiguity about which to pick for the same kind values.

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?

Usage is only implied: the matching rules ('names or code prefixes') and the note that 'plans can use either the names or the codes' hint at when this is needed as a resolution step. There is no explicit when-to-use versus browse_codes, and no stated exclusions or prerequisites.

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