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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is covered. The description adds meaningful behavioral context: house data comes from the Congress.gov API while senate data comes from the Senate's LIS feed, list returns newest first by default, and 'get' returns specific fields (question, result, tallies, party breakdown, associated bill/nomination/amendment). This goes beyond the annotations without contradicting them.

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 three sentences, front-loaded with the core purpose, and each sentence earns its place. It efficiently packs chamber sourcing, operation types, and return content without redundancy or filler. The structure is scannable and immediately actionable for an agent.

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?

The description covers operation semantics, chamber selection, data sources, and default ordering. The input schema documents all parameters, and an output schema exists, so return values are already specified. Minor gaps like pagination behavior are handled by the schema; overall, the agent has everything needed to select and invoke the tool correctly. A 4 is appropriate given the tool's complexity.

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%, so the baseline is 3. The description does not add much parameter-level meaning beyond the schema: it mentions operation-to-parameter mapping and the chamber data source, but the schema already documents voteNumber's requirement for 'get'/'members' and the chamber-specific roll call reset behavior. No significant param semantics are added 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 opens with a specific verb-resource pair ('Retrieve U.S. congressional roll call votes and individual member voting positions') and immediately distinguishes the tool's domain from the sibling tools (bill lookup, committee reports, etc.). It further clarifies scope by chamber and by operation, leaving no ambiguity about what the tool does.

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 operation selection guidance: 'Use 'list'...', 'get' for vote details..., or 'members' for how each member voted.' It also distinguishes data sources for house vs senate. It does not explicitly state when not to use this tool versus a sibling, but the sibling tools are clearly different domains, so exclusion guidance is unnecessary.

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