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

The description only restates what the tool does without adding behavioral context. Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, but the description does not elaborate on what a 'timeline' includes, ordering, date ranges, or any other behavioral traits. It adds no value beyond the title.

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 a single, clear, and front-loaded sentence with no unnecessary words. It earns every character and is appropriately concise for a simple tool.

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?

The tool is simple with one parameter, has an output schema, and is accompanied by safety-related annotations, so the description does not need to explain return values. However, it lacks usage guidance and behavioral context, making it minimally viable but not fully complete for a tool with a large sibling family.

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 schema has one parameter 'domain' with no description (0% coverage). The description's phrase 'for a domain' only repeats the parameter name and does not add meaningful semantics such as expected format, examples, or constraints. The parameter meaning is self-evident from its name, but the description fails to compensate for the lack of schema-based documentation.

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' and clearly identifies the resource as 'CT certificate timeline' for a domain. It distinguishes itself from sibling tools like get_ct_certificates by focusing on a timeline rather than the certificates themselves.

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 provides no guidance on when to use this tool versus alternatives such as get_ct_certificates or get_domain_history. It lacks any mention of specific use cases, prerequisites, or comparison with related tools.

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