Skip to main content
Glama
AshwinSundar

Congress[.]gov MCP Server

by AshwinSundar

get_treaty

Retrieve treaty information from the Congress.gov API by specifying congress number, treaty number, date ranges, and pagination parameters.

Instructions

Retrieve treaty information from the Congress.gov API. Full documentation for this endpoint -> https://github.com/LibraryOfCongress/api.congress.gov/blob/main/Documentation/TreatyEndpoint.md

Args: congress: Congress number (e.g., 118 for 118th Congress) treaty_number: Specific treaty number offset: Starting record (default 0) limit: Maximum records to return (max 250, default 20) from_datetime: Start timestamp (YYYY-MM-DDTHH:MM:SSZ format) to_datetime: End timestamp (YYYY-MM-DDTHH:MM:SSZ format)

Returns: dict: Treaty data from Congress.gov API

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
congressNo
treaty_numberNo
offsetNo
limitNo
from_datetimeNo
to_datetimeNo

Implementation Reference

  • The handler function for the 'get_treaty' MCP tool. It is decorated with @mcp.tool() which registers it with the MCP server. The function constructs a URL and parameters for the Congress.gov /treaty endpoint and fetches data using requests, handling errors appropriately. Input schema is inferred from the function parameters.
    @mcp.tool()
    async def get_treaty(
        congress: int | None = None,
        treaty_number: int | None = None,
        offset: int = 0,
        limit: int = 20,
        from_datetime: str | None = None,
        to_datetime: str | None = None
    ) -> dict:
        """
        Retrieve treaty information from the Congress.gov API. Full documentation for this endpoint -> https://github.com/LibraryOfCongress/api.congress.gov/blob/main/Documentation/TreatyEndpoint.md
    
        Args:
            congress: Congress number (e.g., 118 for 118th Congress)
            treaty_number: Specific treaty number
            offset: Starting record (default 0)
            limit: Maximum records to return (max 250, default 20)
            from_datetime: Start timestamp (YYYY-MM-DDTHH:MM:SSZ format)
            to_datetime: End timestamp (YYYY-MM-DDTHH:MM:SSZ format)
    
        Returns:
            dict: Treaty data from Congress.gov API
        """
        base_url = "https://api.congress.gov/v3/treaty"
    
        url = base_url
        if congress:
            url += f"/{congress}"
            if treaty_number:
                url += f"/{treaty_number}"
    
        params = {
            "api_key": congress_gov_api_key,
            "format": "json",
            "offset": offset,
            "limit": min(limit, 250)
        }
    
        if from_datetime:
            params["fromDateTime"] = from_datetime
        if to_datetime:
            params["toDateTime"] = to_datetime
    
        try:
            response = requests.get(url, params=params)
            response.raise_for_status()
            return response.json()
    
        except requests.exceptions.RequestException as e:
            return {
                "error": f"Failed to retrieve treaty information: {str(e)}",
                "status_code": getattr(e.response, "status_code", None)
            }
  • server.py:1135-1135 (registration)
    The @mcp.tool() decorator registers the get_treaty function as an MCP tool.
    @mcp.tool()
Behavior3/5

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

With no annotations provided, the description carries the full burden. It discloses that it retrieves data from an external API and mentions default values and limits (max 250 records), which adds useful context. However, it doesn't cover important behavioral aspects like error handling, authentication requirements, rate limits, pagination behavior beyond offset/limit, or what happens when parameters are null. The link to documentation partially compensates but isn't self-contained.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-structured with a clear purpose statement, documentation link, parameter details in a formatted Args section, and return value description. It's appropriately sized for a 6-parameter tool. The documentation link is useful but could be more integrated. Every sentence earns its place, though the 'Returns' line is somewhat vague.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given 6 parameters, no annotations, and no output schema, the description is moderately complete. It covers all parameters and mentions the API source, but lacks details about the return structure (beyond 'dict'), error conditions, authentication, or rate limiting. For a read-only API tool with multiple filters, more behavioral context would be helpful, though the parameter documentation is solid.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate. It provides clear explanations for all 6 parameters: congress number, treaty number, pagination controls (offset/limit), and datetime filters with format examples. This adds significant meaning beyond the bare schema. However, it doesn't explain parameter interactions (e.g., how treaty_number affects other filters) or what 'null' values mean for optional parameters.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: 'Retrieve treaty information from the Congress.gov API.' It specifies the verb ('Retrieve') and resource ('treaty information'), and distinguishes it from siblings by focusing on treaties rather than bills, amendments, etc. However, it doesn't explicitly differentiate from hypothetical treaty-related siblings beyond naming the endpoint.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives. It mentions the API endpoint documentation but doesn't explain when treaty retrieval is appropriate compared to other data types (bills, members, etc.) available in the sibling tools. There's no mention of prerequisites, typical use cases, or constraints beyond parameter defaults.

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

Install Server

Other Tools

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/AshwinSundar/congress_gov_mcp'

If you have feedback or need assistance with the MCP directory API, please join our Discord server