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

Annotations only declare the mutation profile (readOnly=false, idempotent=false, openWorld=false, destructive=false); the description goes well beyond that by disclosing session scoping, a hard cap of 10 watches, the 24h maximum, the default watch length, and an attribution requirement. It also discloses ambiguity handling — a name fitting several places returns a which-one list and opens nothing — which is exactly the kind of behavior an agent cannot infer from the schema.

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?

Front-loaded with purpose, then usage, then the behavioral caveats, and every clause carries information (limits, attribution, ambiguity, the no-lookup shortcut). The middle is dense with stacked examples, which is slightly crowded but not 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?

There is no output schema, and the description compensates by explaining what a watch reports per kind, how ambiguity and conditions are echoed back, session scope, and the watch cap. For a state-creating tool with a nested condition object, every fact an agent needs before calling it is present.

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% and the schema already explains key/kind resolution, hours vs until mutual exclusivity, language, and every condition sub-key with examples. The description restates the hours cap/default and that condition narrows the watch, adding a little framing but no syntax beyond what the schema carries. Baseline 3 is appropriate when the schema does the heavy lifting.

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 — 'Opens a watch so THIS conversation is told when something changes' — and enumerates the change types (road reopening, stop late, weather warning, charger free). The closing 'Do NOT use to look up now' cleanly separates it from the large family of check_* / find_* read siblings, so an agent can route correctly without opening a 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?

Gives explicit when-to-use with quoted user phrasings ('sag mir Bescheid, wenn die A8 wieder frei ist'), explicit when-not ('Do NOT use to look up now, nor for e-mail, SMS or any alert outside this chat'), and even instructs the agent what to tell the user in that case. It also warns 'A name is enough as the key; no lookup first', heading off the obvious wrong behavior of resolving via a read tool first.

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