nist-mcp

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

Annotations only indicate readOnlyHint=false, but the description adds valuable context: it specifies the return type ('Returns the file path'), mentions caching behavior ('to local cache'), and clarifies the dependency on get_publication for material_index usage, enhancing understanding beyond basic 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?

Two concise sentences front-load key information: the download action and return value, followed by usage guidance for material_index. Every sentence earns its place with no wasted words.

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 moderate complexity, rich annotations, and the presence of an output schema (which handles return value details), the description is complete enough. It covers purpose, usage context, and behavioral aspects without needing to repeat structured data.

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?

With 100% schema description coverage, the schema already documents both parameters well. The description adds some meaning by explaining material_index's relation to get_publication output, but does not significantly enhance parameter understanding beyond what the schema provides.

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 action ('Download'), resource ('publication PDF or supplemental material'), and destination ('to local cache'), distinguishing it from siblings like get_document_content or get_publication by focusing on file retrieval rather than content/metadata access.

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?

It provides clear context for when to use material_index ('to download a specific supplemental file listed in the get_publication output'), but does not explicitly state when not to use it or name alternatives among siblings, leaving some guidance implicit.

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