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

Annotations already declare destructiveHint=true, readOnlyHint=false, idempotentHint=false, so the write nature is known. The description adds valuable behavioral context: approval requirements ('first use may require a manager's approval'), the 'card is the yes — do not re-ask' behavior, and the recurring-tag convention that complete_commitment reads. It doesn't contradict annotations. A small gap: it doesn't explicitly state what happens on approval denial, but the approval behavior is well covered.

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 dense but well-organized: purpose first, then usage triggers, then pairing guidance, then approval behavior. Every sentence earns its place, though the approval note is a bit long and could be tightened. The front-loading of 'ALWAYS use this (not save_knowledge)' is effective.

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 6-param write tool with no output schema, the description covers the key decision points: when to use, how to handle event dates, how to mark recurring commitments, and approval behavior. It doesn't explain return values, but there's no output schema and the 'card is the yes' hints at the result. Minor gaps: no explicit mention of what happens if the user is ambiguous about the prep deadline, but the 'confirm with the user' instruction covers 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 description coverage is 100%, so the schema already documents all 6 parameters. The description adds meaningful semantic value beyond the schema: it explains the due_date prep-deadline reframing for events (default ~7 days before, store actual date in description), the recurring-tag convention for description, and the domain field's scope. This goes beyond baseline 3 by clarifying non-obvious parameter behavior.

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 and resource ('Track a personal commitment, deadline, birthday, appointment, or obligation') and explicitly distinguishes it from save_knowledge by listing concrete triggers (birthdays, due dates, deadlines, tax filings, events to plan, gifts to send). This makes the tool's purpose unmistakable and differentiates it from 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?

The description explicitly says 'ALWAYS use this (not save_knowledge) when the user mentions...' and provides a list of examples. It also gives guidance on pairing with save_knowledge for supporting context, and explains approval behavior ('call it on the first clear ask; the card is the yes — do not re-ask in chat'). This is exemplary usage guidance.

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