nist-mcp

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows this is a safe, repeatable read operation. The description adds valuable behavioral context beyond annotations: it explains the hierarchical browsing behavior (functions → categories → subcategories), includes full-text search capability, and mentions that results include 'count of mapped SP 800-53 controls per entry.' This provides useful operational context that annotations don't cover.

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 extremely concise and well-structured. It uses a single paragraph with clear, bullet-like examples that efficiently communicate the tool's behavior. Every sentence earns its place by providing essential usage information without any fluff or repetition.

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 that annotations cover safety (read-only, idempotent), schema coverage is 100%, and there's an output schema, the description provides exactly what's needed. It explains the hierarchical browsing/search behavior, gives concrete usage examples, and mentions the additional data included (SP 800-53 control counts). No gaps remain for this type of query 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?

Schema description coverage is 100%, so the schema already documents all four parameters thoroughly. The description adds some semantic context with usage examples (e.g., 'function="PR" = Protect categories'), but doesn't provide significant additional meaning beyond what's in the schema descriptions. This meets the baseline of 3 when schema coverage is high.

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 the tool's purpose: 'Browse/search the NIST CSF 2.0 framework hierarchy.' It specifies the exact resource (NIST CSF 2.0 framework) and the action (browse/search), distinguishing it from siblings like 'get_framework_mappings' or 'search_nist' by focusing specifically on the CSF hierarchy.

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 provides explicit usage guidelines with examples for different parameter combinations: 'No args = list all 6 functions. function="PR" = Protect categories. category="PR.AC" = subcategories. query="risk" = full-text search.' This clearly indicates when to use specific parameters versus alternatives, though it doesn't name sibling tools explicitly.

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