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

Annotations already convey write, idempotent, and non-destructive intent. The description adds valuable behavioral context beyond that: this action creates a persistent record (Case Passport) and a permanent address, and it warns that the connect_token expires shortly after lookup. 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?

Three sentences with no redundancy: the main effect, the usage trigger, and the requirement. The most important information is front-loaded, and no space is wasted repeating schema or annotation content.

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 mutation tool with no output schema and a full annotation set, the description is complete. It explains the action, the side effects, when to use it, and the dependency on a short-lived token. No critical gaps remain for correct invocation.

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%, so the parameters are already well documented, giving a baseline of 3. The description adds one useful parameter-level insight: the connect_token has a short expiry window and must be used promptly. It doesn't add detail on user_role, but the schema's 'Ask them rather than guessing' already covers that.

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 the specific verb and resource: 'Save a case that find_federal_case just located to the signed-in CaseMagic account.' It also states the concrete effects (creates the Case Passport and a permanent CaseMail address), which distinguish it from read-only siblings like get_case_passport and from lookup tools like find_federal_case.

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?

It gives an explicit trigger condition: 'Use this after the user has confirmed which case is theirs and wants CaseMagic to keep it.' It also ties the tool to the correct workflow step by requiring the connect_token from find_federal_case, whose short expiry is flagged. This unambiguously tells the agent when to invoke it.

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