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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered; the description adds genuinely new behavior detail: results are in the person's timezone, colleague calendars appear only as busy blocks while the person's own shows full detail, and unresolved past calls are included. It omits any note about result volume or how many events a 31-day window may return.

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 purpose and timezone scoping are front-loaded in the opening clause, and the example queries at the end are useful rather than filler. The middle portion is a dense run-on sentence that packs several distinct facts together, which costs a little readability but no wasted content.

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 does the work of explaining what comes back, including the full-vs-busy distinction and the call attributes, which is unusually complete for a list tool. The remaining gap is that "this person" is never defined (presumably the authenticated user via whoami), which matters for a multi-user workspace.

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 `days` and `from` are already documented with defaults and constraints. The description adds only the loose notion of "day by day", which aligns with but does not extend the windowing semantics in the schema. Baseline 3 applies 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?

The description clearly states the resource (a person's day-by-day calendar) and the two content types it returns: booked lead calls with their attributes, and connected Google Calendar events. It does not explicitly name which sibling to use instead of it (e.g. get_call for a single call, search_calls for lookup), so sibling differentiation is implied by content rather than stated.

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?

It gives concrete triggering queries ("what's on today", "when am I meeting Acme") and a secondary use case (surfacing calls that ended with no reported outcome), which is strong forward guidance. It offers no explicit exclusions or named alternatives, so an agent must infer that point-lookups belong to get_call/get_lead.

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