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

Annotations already declare destructiveHint=true and readOnlyHint=false, and the description adds substantially more: the concrete consequence that existing ciphertexts become permanently unreadable, plus the auth requirement and the fact that start_login does not unlock this tool. This is exactly the extra context the annotations cannot convey.

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 destructive warning is front-loaded in the first sentence, which is the right ordering. The ACCESS paragraph is somewhat boilerplate and slightly verbose, but each part (warning, prerequisite, auth steps) carries actionable information.

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 destructive one-parameter tool with no output schema, the description covers the critical unknowns: irreversibility, auth prerequisites, and the workaround path. It falls short only in not relating the tool to its near-neighbor delete_hitl, which would help disambiguation.

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?

There is a single parameter (hitl_id) with 100% schema description coverage, so the schema already documents it fully. The description adds no syntax, format, or sourcing detail for the ID, which is acceptable given the high coverage but earns only the baseline.

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?

States a specific verb and resource: 'Delete the encryption keypair from a HITL config.' This distinguishes it from siblings such as delete_hitl, get_hitl_keys, and upload_hitl_keys, so an agent can identify the exact target of the operation without opening any schema.

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 a clear prerequisite ('needs a Proof account', authenticate then retry) but never states when to choose this tool over alternatives like delete_hitl, nor when not to delete keys. Prerequisite guidance is present; alternative-selection guidance is absent.

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