get_today_items

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds substantial context beyond them: rollover inclusion semantics, timezone resolution order, the caveat that today's recurring tasks may be missing until the client generates them, and an explicit note that clock-time items are untested. This is unusually candid behavioral disclosure.

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 core selection rule and the sibling exclusion are front-loaded, which is correct. The trailing provenance note ('Observed 2026-09-11...') and untested-clock-time remark are useful but slightly verbose, keeping it short of a 5.

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?

An output schema exists, so return values need not be described. Given that, the description covers the selection semantics, the alternative tool, timezone handling, and known staleness caveats — nothing an agent needs to invoke it correctly is missing.

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 parameter's schema description already states the YYYY-MM-DD format, the day <= date behavior, and the timezone fallback. The description largely restates this, so the baseline of 3 is appropriate.

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 (open tasks/projects) plus the exact selection rule (day <= date, including rollover items, not just items on that day). It also distinguishes itself from the sibling get_due_items, which handles deadline-only tasks.

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 names the alternative for the excluded case ('Tasks that only have a deadline are not included; fetch them with get_due_items'), giving a clear when/when-not routing rule. The default-timezone behavior of omitting the date is also spelled out.

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