congress_bill_cosponsors

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

The description adds that the tool returns individual cosponsor details including party and dates, which goes beyond the readOnlyHint annotation. However, it does not disclose potential behavioral traits like pagination, rate limits, or authorization needs. With annotations already covering read-only, the description provides moderate additional value.

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 two sentences long, front-loads the action, and contains no extraneous words. Every sentence earns its place by stating the primary function and differentiating from a sibling.

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 tool has no output schema, so the description should ideally explain the return structure more fully. It mentions party affiliation and sponsorship dates but does not detail fields like type of cosponsor, date format, or pagination behavior. The description is adequate but not thorough for a list tool with 5 parameters.

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?

All parameters in the input schema have descriptions (100% coverage). The tool description does not add meaning beyond what the schema already provides, such as explaining the format of dates or the default limit. According to rules, high schema coverage yields a baseline of 3, which is met.

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 clearly states the tool's purpose: 'Get the full list of cosponsors for a bill with party affiliation and sponsorship dates.' It also explicitly distinguishes from the sibling tool congress_bill_details, which provides only a party breakdown summary, making the purpose unambiguous.

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 contrasts with congress_bill_details, telling when to use this tool (for individual cosponsor details) vs the other (for party breakdown summary). It does not explicitly state when not to use, but the context is clear. A 4 is appropriate.

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