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

With no annotations, the description carries the full burden and does so: it discloses that removal is a destructive side effect, that the watch will no longer be checked, the exact JSON return shape ({ removed, ok: true }), and the conditional authentication requirement. This is exactly the context annotations would otherwise need to supply.

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?

Four sentences, front-loaded with the action and its destructive effect, then the return value, then the auth rule. No filler; the parenthetical clarifying the deletion side effect is the only emphasis and it earns its place.

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?

Although there is no annotation coverage and no output schema, the description still explains the destructive effect, the return payload, and the conditional verification flow for all four parameters. Nothing an agent needs to call this correctly is missing.

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 baseline is 3, but the description adds conditional meaning the schema does not convey: email and code vs. sessionToken are alternative verification paths that only apply when the watch has an email. The id parameter's dual role (watch id or mark name) is left to the schema.

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 opens with a specific verb and resource ('Stop watching a mark') and immediately clarifies that this deletes the watch. That is enough to separate it from the sibling watch_mark (which creates a watch) without opening either 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?

It states the prerequisite condition explicitly: an email-bearing watch requires proof of ownership via email plus a 6-digit code from request_watch_code, or a session token, while a watch with no email needs no verification. It does not name watch_mark or list_watches as alternatives for agents that may have called the wrong tool.

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