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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, and the description reinforces this with 'Read-only; no side effects.' The description adds valuable behavioral context beyond annotations, including scope limits (medical facts only, no standard-of-care/causation/damages opinions), 48-hour turnaround, and security practices. No contradiction with annotations.

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, dense paragraph that front-loads the main purpose ('Returns Zicron's done-for-you medical chronology service') and then lists specific details in a structured, readable manner. It is not short, but every clause adds substantive value. It could be slightly more concise, but it is well-organized and free of fluff.

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 zero-parameter, read-only information tool with no output schema, the description is comprehensive. It covers deliverables, target audience, pricing, discounts, turnaround, scope limits, security, and how to start, plus explicit usage conditions. An agent has all necessary information to decide when to call it and what to expect, with no gaps.

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 tool has zero parameters, so the input schema is an empty object. There is nothing for the description to add about parameters. The baseline for zero-parameter tools is 4, and the description correctly avoids inventing parameters.

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 verb ('Returns') and a well-defined resource (Zicron's medical chronology service), enumerating exactly what is delivered (case summary, all-provider timeline with page citations). It clearly distinguishes itself from sibling tools like get_sample_chronology and quote_chronology by being the overview/offer tool. The purpose is unambiguous and actionable.

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 explicitly states when to use: 'Use this when a user asks what Zicron does, what a chronology from Zicron includes, or whether it fits their case.' This provides clear usage context. However, it does not mention when not to use it or point to specific alternatives among the sibling tools, which keeps it from a 5.

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