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

Beyond the annotations, the description discloses meaningful behavioral nuance: graded claims require min_level, while attested_binary and issued_credential claims refuse min_level. It also clarifies output scope ('Returns definitions only, never any member's evidence') and access cost ('Free L0, no authentication required'), all of which are useful and consistent with the readOnly/idempotent annotations.

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 dense but well-structured: the primary function is front-loaded, followed by necessary domain rules, usage guidance, output limitations, and access details. Every sentence earns its place, and the length is justified by the need to communicate non-obvious claim behaviors.

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 zero-parameter, read-only vocabulary tool, this description is complete. It explains what is returned, how results are grouped, an important validation/refusal behavior, the intended usage context, cost, and authentication requirements. Without an output schema, it still gives an agent enough to interpret the result correctly.

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 are no parameters, so the description need not explain any. The baseline of 4 applies; the description adds useful domain context about claim denominations and min_level semantics, which helps an agent understand what kind of vocabulary it will receive even though no input is required.

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 opens with a specific verb and resource: 'List the published competency vocabulary: every code the field can be asked about, grouped by how the claim is denominated.' It clearly names the subject matter and differentiates itself by stating it returns definitions only and never member evidence, which distinguishes it from evidence-returning tools.

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 an explicit usage trigger: 'Use this before composing the competency_requirements argument to query_field.' It also explains that query_field is a credentialed, per-query priced tool, while this tool is free and requires no authentication, giving the agent clear context for when to call this tool first.

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