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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so safety is covered. The description goes beyond them by disclosing ranking behavior ('common terms such as cybersecurity or janitorial list their usual codes first'), prefix-expansion behavior for digits, and a required output presentation step (print each opportunities_url as a markdown link).

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-loaded with the triggering condition and free of filler, but the middle paragraph is tightly packed and mixes query semantics, limits, and cross-tool routing into dense clauses. Still, every sentence carries information.

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?

An output schema exists so return values need no explanation, annotations cover the safety profile, and the description supplies usage triggers, query semantics, routing to consumers, and output formatting. Nothing an agent needs to call this correctly is 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 coverage is 100%, so baseline is 3, but the description adds real meaning beyond the schema: the 2-100 character bound is restated with a concrete purpose, and it explains that a 2-6 digit query returns every six-digit code starting with those digits. The 'usual codes first' ordering for common words is also semantics the schema does not carry.

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 opening sentence names a specific verb+resource (look up a NAICS code) and states the two triggering intents: describing a line of work in words, or asking what a code/prefix covers. It is clearly distinguishable from the sibling search_* tools, which it explicitly routes codes to.

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?

Provides explicit when-to-use ('the user describes a line of work in words and a NAICS code is needed'), explicit when-not-to-use ('Do not use for searching opportunities or awards themselves'), and names the alternative tools to hand codes to. Nothing is left to inference.

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