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

Annotations only declare the mutation/idempotency profile, while the description adds substantial context: numeric validation bounds (5-480 min meetings, 120 min buffers, 1-90 day window, notice < window), the slug redirect behavior and the refusal case, and an authorization constraint on required_attendees calendars. That is exactly the value-add expected on top of annotations.

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 main verb is front-loaded, but the body is a dense semicolon-chained wall of validation rules that is hard to scan. Every clause carries information, yet the phrasing 'as its editor saves them' is vague and the structure could be broken into clearer segments.

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 22-parameter mutation tool with no output schema and ~45% schema coverage, the description covers the mutation semantics and validation rules well but leaves roughly half the parameters undocumented and says nothing about the response. Adequate but with clear gaps.

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 only 45%, but the description compensates for a few key parameters: working_hours encoding (weekday 0-6 to [from,to] HH:MM windows, omitted day = not worked), slug semantics, and required_attendees constraints. Many of the 22 parameters (name, timezone, agent_job, consent_*, captcha_enabled, invitee_fields) remain unexplained in both schema and description.

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 ('Change an event's settings') and clarifies it is a partial/editor-driven update ('only what is named changes'). It is distinguishable from create_an_event and publish_an_event by implication, but never names those siblings, so an agent must infer the boundary.

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?

There is no explicit when-to-use guidance and no mention of alternatives such as create_an_event or publish_an_event. The only usable signal is the implicit partial-update semantics ('only what is named changes'), which is more behavioral than routing guidance.

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