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

Annotations already declare readOnlyHint and idempotentHint, but the description goes far beyond by explaining nuanced behavior: how graded claims require min_level while binary claims refuse min_level. It also discloses that no authentication is required, adding operational context not present in 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 front-loaded: the first clause states the primary action. It uses three sentences to cover purpose, behavioral nuance, and usage, with no fluff. The only slight excess is the 'Free L0, no authentication required' clause, but it adds operational value. Overall well-structured.

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 no-parameter, no-output-schema definitional tool, the description provides complete context: what it lists, how items are grouped, special behaviors for claim types, a usage context, and operational constraints. The absence of return-format details is acceptable given the nature of the 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?

The tool has zero parameters; schema coverage is trivially 100%. The baseline for zero parameters is 4, and the description appropriately focuses on the output semantics rather than parameters, so no deduction is needed.

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 'List the published competency vocabulary', providing a specific verb and resource. It clearly distinguishes this from siblings like describe_traits and list_archetypes by focusing on competency codes and their denomination groups. The scope is explicitly defined as 'every code the field can be asked about'.

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 a clear usage directive: 'Use this before composing query_field competency_requirements'. It also implicitly distinguishes from member-data tools by stating 'Definitions only, no member evidence'. However, it does not explicitly mention alternatives or conditions when not to use it.

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