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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so safety is covered. The description adds genuinely new behavior: partial-failure semantics ('Invalid registrations come back in invalid[]') and the auth requirement (account connection via OAuth/account key, not a system key).

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 short sentences, front-loaded with the action and its scoping guarantee, then the failure-mode note, then the prerequisite. No sentence is redundant.

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?

With annotations covering safety/idempotency, an output schema covering returns, and 100% parameter coverage, the description supplies exactly the missing pieces: auth requirements, non-clobbering scope, and partial-failure handling. Nothing an agent needs to call it correctly is absent.

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% for the single parameter, including format and min/max constraints, so the schema carries the load. The description adds no format or syntax detail beyond it, making the baseline 3 appropriate.

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 ('Remove registration(s) from this account's watch list') and scopes it precisely with 'WITHOUT touching the rest', which distinguishes it from whole-list siblings like jt_watch_set and jt_watch_add.

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 'WITHOUT touching the rest' clause implicitly tells the agent to prefer this over a set/replace operation when removing a subset, and the auth sentence establishes the connection prerequisite. It stops short of naming jt_watch_set or jt_watch_remove_rule as the explicit alternative.

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