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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world scope, so the safety profile is covered. The description adds the return-shape context (spend, firms, issue codes, filings) but says nothing about data recency, coverage limits, or behavior when the client substring matches multiple companies — a real ambiguity for a substring match.

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?

One sentence, front-loaded with the aggregate verb and resource, then the field list. No filler and nothing that could be cut without losing information.

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 usefully enumerates the returned fields, and annotations cover the safety profile, so an agent has enough to call it. The remaining gap is the lack of sibling differentiation and any note on substring-match ambiguity or result limits.

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% and the schema itself documents the single 'client' parameter as a substring match. The description only reinforces 'for one company' and adds no further syntax, matching rules, or handling for ambiguous substring hits. 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?

The description names a specific verb (Aggregate), a precise resource (Senate Lobbying Disclosure dossier), and a scope ('for one company'), then enumerates what the dossier contains. This clearly separates it from the issue-oriented sibling lobbying_by_issue, though it never names that sibling explicitly.

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?

Usage is implied by 'for one company' — an agent can infer this is the company-keyed path versus lobbying_by_issue — but there is no explicit when-to-use guidance, no stated alternatives, and no exclusions or prerequisites.

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