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

Annotations already declare readOnly/openWorld/non-destructive, and the description goes well beyond by disclosing exactly what v1A returns (metadata only) versus what is deliberately not included (sponsors, cosponsors, action history, text, CRS summaries), plus the 'pure-publisher, no predictions' posture. This is rich behavioral context not present in structured fields.

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?

Front-loaded with purpose and usage before details, and every section serves a purpose. It is lengthy and the full bill-type enumeration partially duplicates the bill_type enum already documented in the schema, which is mild redundancy, but overall it is well organized and skimmable.

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?

With no output schema, the description carries the full burden of describing returns and does so explicitly (title, type+number, originating chamber, latest action, links) and redirects to api_url/congress_gov_url for detail. Nothing an agent needs to call this 12-param, all-optional tool correctly is missing.

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%, so the baseline is 3, but the description adds genuine meaning beyond the schema: the composite {congress}-{TYPE}-{number} key format, that bill_id is the fastest direct-lookup path, and the semantic distinction between latest-action filters and introduction-date filters. It reinforces rather than merely repeats the schema.

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?

States a specific verb+resource (returns congressional bill metadata) plus scope (all bill types, from api.congress.gov). It explicitly distinguishes itself from siblings by naming the roll-call-vote bridge use case and pointing prose detail to other sources, so an agent can tell what it does versus get_roll_call_votes or unified_search.

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?

Gives an explicit when-to-use list mapped to concrete user questions (bills this Congress, status of a specific bill, House vs Senate volume, topic mentions, roll-call bridge). It also names the fastest path (use bill_id) and disambiguates since/until vs introduced_since in the schema. Alternatives and exclusions are covered.

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