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

The description goes beyond annotations by disclosing the required OAuth scope (watches:write) and the mandatory Idempotency-Key, which are concrete operational constraints not inferable from the annotations alone. Since readOnlyHint and destructiveHint already cover the operation's safety profile, the additional auth and idempotency requirements earn credit here.

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 two short sentences, front-loads the core purpose, and adds only the essential prerequisites. There is no fluff or redundant restating of the tool name.

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 an update tool with 8 parameters, no parameter descriptions, and no output schema, this description is too sparse. It omits crucial behavioral context such as whether omitted optional fields are unchanged, whether the update is partial or full, and what the response contains after the update succeeds.

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 0%, yet the description adds no meaning about any of the 8 parameters. It says 'Update fields' but does not explain which fields are updatable, how partial updates behave, or what values like mode, threshold, or category mean beyond their raw schema constraints.

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 states a specific verb ('Update') and a specific resource ('one owned Founding Pro watch'), which clearly indicates this modifies an existing watch rather than creating or listing one. It is clear enough, but it does not explicitly name or contrast sibling tools such as create_watch or acknowledge_watch to further differentiate.

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 phrase 'one owned Founding Pro watch' implies the tool should be used when modifying an existing watch you own, and the requirement for watches:write provides a prerequisite. However, it does not explicitly state when to prefer this over create_watch or acknowledge_watch, nor does it describe exclusions or scenarios where an alternative would be more appropriate.

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