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

Annotations already declare readOnlyHint/idempotent/non-destructive, so safety is covered. The description adds return-shaping context the annotations do not: results are ranked lists of top clients ordered by reported spend, and codes are enumerated at a specific API path. It stops short of stating result limits or pagination.

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?

Three short sentences: purpose first, input handling second, code-discovery pointer last. No filler and nothing redundant with the schema.

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 burden of explaining returns and does so at a high level ('top clients by reported spend'), plus supplies the code vocabulary. Missing count/pagination and spend-unit details keep it from a 5, but it is sufficient to call the tool correctly.

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 parameter is already documented, but the description adds real meaning beyond it by glossing sample codes as issue domains (HCR health, DEF defense, ENG energy, TRA transport) and pointing to the full code list endpoint. This helps an agent supply a valid code rather than guessing.

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-plus-resource ('who lobbies the federal government on a given issue') and names the exact output lens ('top clients by reported spend'). An agent can distinguish this issue-oriented view from the client-oriented sibling 'lobbying_by_client' without opening either schema.

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 gives the code-discovery path ('/api/v1/lobbying/issues') and the required input shape, which implies usage, but never states when to pick this over 'lobbying_by_client' or other influence tools (e.g. influence_chain, cluster_buys). Guidance is implied rather than explicit.

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