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

Annotations already cover the read-only, non-destructive profile, and the description still adds substantial context: it is free, it returns status (active/expired/stopped), conditions, last-checked time, fire count, and the last 20 fires including webhook delivery outcome, and it discloses the auth failure behavior. That is well beyond what the annotations 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 return payload is front-loaded in a single dense sentence and cost ('Free') comes first. It is slightly run-on with the long enumeration of fire fields, but every clause carries 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?

There is no output schema, so enumerating returned fields is essential and it does so thoroughly, including the 20-fire history and webhook delivery status. Auth requirements and failure modes are also covered, leaving nothing an agent needs before calling it.

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 already explains both parameters, so the baseline is 3. The description adds value by tying the secret to create_watch and explaining the error semantics for a wrong secret or unknown id, which the schema does not state.

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 ('Reads one watch made with create_watch') and immediately scopes it to a single watch rather than a list. This cleanly separates it from create_watch and stop_watch among the siblings.

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?

Explicitly ties usage to a watch created by create_watch and states that watch_id and secret from that call are required, plus the error case for unknown id or wrong secret. It stops short of explicitly naming alternatives (e.g. 'use stop_watch to stop, create_watch to create'), but the context is clear.

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