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

Annotations already mark the tool as read-only and idempotent. The description adds useful behavioral context beyond that: results are ordered oldest-to-newest, include a total count, and cover every matching deal. It could mention empty-result behavior, but this is a minor gap.

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 one front-loaded sentence containing the core facts—scope, ordering, and count—followed by a concrete example. There is no filler or redundancy; every part earns its place.

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 simple two-parameter read-only tool with no output schema, the description is nearly complete: it communicates input, scope, ordering, and result count. It does not specify the exact output record shape or empty-result behavior, but these are minor for the stated use case.

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?

The input schema provides full 100% coverage for both parameters and already explains matching semantics and the optional _apiKey. The description repeats an example but does not add meaningful parameter details beyond what the schema already provides, so 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 states a specific operation ('Get every FTC HSR early-termination notice'), a clear resource scope ('mentioning a given company or fund'), and a clear boundary: a full antitrust-clearance history across every deal. This differentiates the tool from siblings like hsr_recent or hsr_search even without naming them.

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 clearly implies when to use it: when a complete HSR early-termination history for one party is needed, with ordering from oldest to newest. It does not explicitly contrast with alternatives or list exclusions, but the use case is clear enough for an agent to select it appropriately.

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