nist-mcp

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

Annotations already indicate readOnlyHint=true and idempotentHint=true, so the agent knows this is a safe, repeatable read operation. The description adds context about 'bidirectional lookup' and references a 'mappings table,' which provides useful behavioral insight beyond annotations. However, it does not disclose additional traits like rate limits, authentication needs, or result format details.

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 highly concise and front-loaded, consisting of two sentences that efficiently convey the tool's purpose and functionality without any wasted words. Every sentence directly contributes to understanding the tool's use case.

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 the tool's complexity (cross-referencing mappings), rich annotations (readOnlyHint, idempotentHint), 100% schema coverage, and the presence of an output schema, the description is largely complete. It effectively explains the core functionality but could benefit from mentioning output structure or error cases, though the output schema mitigates this gap.

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%, with clear descriptions for both parameters (source_id and target_framework). The description adds minimal semantic value beyond the schema, as it does not explain parameter interactions or provide additional context. The baseline score of 3 is appropriate given the high schema coverage.

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: 'Cross-reference frameworks' with specific examples ('What CSF maps to AC-1?' or 'What 800-53 controls implement PR.AC?') and explicitly mentions it performs 'Bidirectional lookup in the mappings table.' This distinguishes it from sibling tools like get_control or search_controls by focusing on cross-framework mappings rather than individual control details.

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 clear context for when to use this tool: for bidirectional mapping lookups between frameworks. It implies usage through example queries but does not explicitly state when not to use it or name specific alternatives among sibling tools (e.g., get_control for single control details).

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