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

Annotations already flag destructiveHint=true and idempotentHint=true; the description adds genuinely new behavioral facts: what is destroyed (the watch and its remembered state), the observable post-condition (check_watch returns not_found), and cost (free). That is exactly the added context the annotations don't carry.

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?

One tight sentence sequence: effect, destruction scope, post-condition, cost, docs link. Front-loaded with the primary action and no 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 destructive single-parameter mutation with rich annotations and a 100%-documented schema, the description covers destruction scope and post-state well. Only minor gaps remain (no auth/permission note, though 'Free' implies no billing), and no output schema exists so return values needn't be explained.

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% and the single watch_id parameter is already described as the w_... id from watch_search, so the schema does the heavy lifting. The description adds no format or lookup guidance beyond what the schema states; baseline 3 applies.

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 (stop watching / delete) and resource (a watch), and explicitly names the effect relative to siblings: check_watch will answer not_found. An agent can distinguish it from watch_search and check_watch without inspecting 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?

Implies the use case clearly (stop watching a saved search) and names the downstream consequence via check_watch, which helps an agent reason about alternatives. It doesn't spell out exclusions or point at watch_search as the way to undo/recreate, but the context is unambiguous.

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