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

While annotations already flag destructiveHint=true, the description adds meaningful behavioral context: 'Stage deletion' reveals the two-phase nature, 'fails if the contact is assigned to active domains' discloses a key failure mode, and 'Requires authentication' and 'Returns an actionId; present the summary to the user, then call executeConfirmedAction' explain the necessary follow-up behavior. This goes well beyond what annotations provide.

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 compact and front-loaded: the core purpose appears first, followed by a DESTRUCTIVE warning, a failure condition, and the mandatory confirmation workflow. Every sentence contributes necessary information without repetition or filler.

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 two-phase destructive tool with no output schema, the description covers everything an agent needs: the staging behavior, failure condition, authentication requirement, the actionId return value, and the exact next tool to call. The required next step, executeConfirmedAction, is explicitly named, making the workflow complete.

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 description coverage is 100%, and both parameters are individually documented in the input schema, including that contactId comes from listContacts and sessionKey is only needed for device login. The tool description does not add additional parameter-level detail, which aligns with the baseline 3 for high schema 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 and resource: 'Stage deletion of a contact.' It clearly distinguishes this from createContact, updateContact, and executeConfirmedAction by explaining it is the staging step, not the final deletion. The additional constraint about active domains adds specificity.

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 indicates when to use the tool: when a contact deletion needs to be staged, and then when to proceed with executeConfirmedAction. It also gives an exclusion condition: fails if the contact is assigned to active domains. It does not explicitly contrast with sibling tools like updateContact, but the workflow guidance is strong enough to route an agent correctly.

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