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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so safety is covered. The description adds useful substance beyond that: it enumerates what the response contains (lobbying companies, their firms, bill title, sponsor, latest action), which is valuable given there is no output schema.

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?

Two sentences, front-loaded with the result set before the input formats. Every clause earns its place given the absence of an output schema, though the return-content enumeration makes the first sentence fairly dense.

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 two-parameter, read-only lookup with no output schema, the description covers what is returned and how to supply the required identifier, and annotations cover the safety profile. The 'congress' parameter's default behavior is left only to the schema, a minor gap.

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 both parameters are already documented. The description reinforces the 'bill' parameter's accepted formats but adds no syntax beyond the schema's own examples, and says nothing about the 'congress' parameter or its default. Baseline 3 is appropriate.

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 precise verb+resource: the companies and organizations whose lobbying reports name a specific bill, plus the firms each uses on it and bill metadata (title, sponsor, latest action). This is clearly distinguishable from siblings like who_lobbies_agency and who_lobbies_on, which target different entities.

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 concrete input guidance by showing accepted bill identifier forms ('H.R. 1', 'S. 1582', 'HR 4366') and title-word forms ('GENIUS Act', 'farm bill'), which tells the agent the tool works with either. It does not name when to prefer this over sibling lookup tools or state any exclusions, so it stops short of a full routing rule.

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