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

With no annotations, the description carries the full burden and does disclose real behavior: paid census work is refused over MCP and instead delivered via x402 on an HTTP endpoint. That refusal semantics is exactly the kind of trait an agent needs, though it doesn't say what the tool actually returns.

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?

A single compact sentence that leads with what the tool is (the explainer for the paid path) before the routing constraint. Nothing is padded, though the sentence packs two ideas and could be split for clarity.

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 zero-parameter informational tool with no output schema, the description covers the essential behavior (explanation + refusal over MCP). It is nearly complete; the only gap is that it never says what the explanation itself contains or how it is returned.

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?

The tool takes zero parameters, so there are no parameter semantics to document; the baseline for a 0-param tool is 4. The description gives no misleading parameter expectations.

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 states a specific function – it explains the paid census path rather than executing a paid census, which notably corrects the impression given by the name 'census_run'. It is clear on its own, though it never references the sibling tools (census_pricing, census_verify, etc.) to differentiate the free vs. paid paths.

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 implicitly tells the agent when this tool will not deliver value: paid work is refused over MCP and must go through x402 on POST /census. That is useful routing information, but it never states when the agent *should* call census_run or which sibling handles the free path.

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