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

Annotations already declare readOnly=true, but the description adds crucial context: 'CMMC Phase II was suspended on 13 July 2026, so C3PAO and DIBCAC assessments cannot currently be designated even where the level calls for one.' This time-sensitive regulatory caveat goes beyond annotations and tells the agent about current real-world limitations.

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?

Two sentences, front-loaded with the core purpose and followed by necessary context. The second sentence includes critical regulatory timing and contract clause examples, all without redundancy. Every 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?

Given no output schema, the description implies the output by stating it 'Determine[s] which CMMC level... and - separately - which assessment type may actually be designated today.' It includes enough context about when to use the tool and the suspension nuance, but does not explicitly describe the return format or whether reasoning is included.

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%, with clear descriptions for 'handles_cui' and 'contract_clauses'. The description adds only marginal semantic value by mentioning 'data they handle' and 'clauses in their contracts', which maps directly to the schema. It does not add syntax or format details beyond 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?

The description clearly states a specific action: 'Determine which CMMC level (1, 2, or 3) applies to a defense contractor based on the data they handle and the clauses in their contracts.' It also distinguishes the separate question of 'which assessment type may actually be designated today,' adding scope that differentiates it from siblings.

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 triggers: 'Call this when the user asks "what CMMC level do I need", whether FCI-only work needs CMMC, or what DFARS 252.204-7012/7019/7020/7021 imply.' It clarifies that the level question and current assessment type question are different, but does not explicitly name alternative tools or state 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.