US Government Open Data MCP

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

Annotations already declare readOnlyHint=true, indicating this is a safe read operation. The description adds useful context about the tool's purpose in the discovery workflow and mentions the return format ('Returns variable IDs'), but doesn't provide behavioral details like rate limits, authentication needs, or pagination behavior. With annotations covering the safety profile, this earns a baseline score for adding some value.

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 front-loaded with essential information in just two sentences. Every word earns its place: the first sentence states the core functionality, and the second explains the workflow relationship and output format. There's zero wasted text.

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 search tool with read-only annotations and no output schema, the description provides good context about the tool's role in the workflow and what it returns. However, it doesn't mention limitations like the maximum results parameter's effect or potential search constraints. Given the tool's moderate complexity and lack of output schema, the description is mostly complete but could be slightly enhanced.

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%, meaning all parameters are well-documented in the schema itself. The description doesn't add any parameter-specific information beyond what's already in the schema descriptions. According to the scoring rules, when schema coverage is high (>80%), the baseline score is 3 even without additional parameter semantics in the description.

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 with specific verbs ('search for Census variable names/codes by keyword') and resources ('Census variable names/codes'). It explicitly distinguishes from its sibling 'census_query' by explaining the relationship: this tool returns variable IDs that can be used with that sibling tool.

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 guidance on when to use this tool ('Helps discover what data is available in a given dataset') and names a specific alternative ('census_query') for the next step after obtaining variable IDs. This clearly establishes the tool's role in the workflow.

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