Open Census MCP Server

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

With no annotations provided, the description carries the full burden. It successfully discloses return values ('Returns matching variables with descriptions and table context') and honestly warns about limitations ('known weak spot', 'basic keyword matching', 'Results may be incomplete'). Minor gap: does not explicitly confirm this is read-only, though implied by 'Discover'.

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?

Perfectly structured with four discrete sentences: purpose (1), usage guidelines (2), return value (3), and limitations (4). No redundancy or filler; every sentence earns its place with high information density.

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 3-parameter discovery tool with 100% schema coverage and no output schema, the description adequately covers purpose, usage context, return behavior, and reliability warnings. Sufficient for an agent to invoke correctly, though could mention authentication or rate limiting if applicable.

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 coverage is 100%, establishing a baseline of 3. The description mentions 'concept or keyword' which aligns with the concept parameter, but does not add syntax details, validation rules, or semantic nuances beyond what the schema already provides via its examples and default values.

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 opens with a specific verb ('Discover') + resource ('Census variables') + mechanism ('by concept or keyword'), clearly distinguishing it from sibling 'get_census_data' (which presumably fetches data by known codes rather than discovering them).

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?

Explicitly states when to use ('when the user describes what they want in plain language and you need to identify the correct variable codes'), effectively implying the alternative (use get_census_data when codes are already known). However, it does not explicitly name the sibling alternative.

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