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

Annotations only declare readOnlyHint=false; the description adds real behavioral context beyond that — the first brief takes a few minutes, the brief card waits and fills in asynchronously, and the agent should stop rather than poll. It omits auth/permission details but covers the key timing and interaction behavior.

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 the core action and routing conditions, then the parameter guidance, then the timing caveat. Dense but every sentence carries load; 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?

With no output schema, the description supplies the needed context: what triggers it, what each brief yields, how long it takes, and how to handle the async result. An agent has enough to call it correctly.

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 enum values are already documented, but the description adds meaning the schema lacks: what each brief actually produces ('relationship' = who needs a reply or nudge, note written; 'branding' = who engaged, next post drafted).

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: turning on 'Your day' and starting the first brief from the inbox. The action is clear and distinct from list/query siblings like my_day or what_your_day_did, though it does not name an alternative explicitly.

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 trigger conditions: call when the user asks to start their day, morning brief, relationship brief, brand brief, or says yes to one. It also prescribes the follow-up action ('say it is being written and stop'), leaving nothing to inference.

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