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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive behavior. The description adds useful context: the FTC source, the meaning of the notice as an early public signal for private-target deals, and the return structure. It does not contradict annotations and adds meaningful behavioral context beyond them.

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 front-loaded with the core operation, and every sentence earns its place: domain context, returned fields, example questions, and an example call. It is moderately detailed but not redundant or bloated.

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?

Even without an output schema, the description states the returned fields and ordering, and the schema provides parameters, defaults, and the max value. For a simple read-only list tool, this is enough for an agent to select and invoke it correctly; the paging detail is covered in the limit parameter description.

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 covers all three parameters with descriptions and defaults, so the description carries little burden. The example call reinforces the days/limit usage but does not add semantics beyond what the schema already provides, keeping this at the baseline for full coverage.

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 uses a specific verb ('Get'), names the exact resource ('FTC HSR early-termination notices'), and specifies ordering ('newest first'). It describes the returned fields and provides concrete example questions, making it easy to distinguish from siblings like hsr_search and hsr_party_history.

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 clear use-case guidance with concrete questions ('what mergers got antitrust clearance recently', 'which deals received HSR early termination this week') and an example call. It does not explicitly say when to prefer this over hsr_search or other HSR siblings, so it lacks exclusion guidance.

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