create_calendar

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

Annotations declare idempotentHint=false and destructiveHint=false; the description makes the non-idempotency actionable by warning that after a timeout the calendar may already exist and list_calendars should be checked first. It also confirms no side effects on existing data and that an ID is returned, adding real value beyond the annotation flags.

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?

Four short sentences, front-loaded with the core action, then exclusions, then constraints, then failure handling. Only the name-length clause is partly redundant with the schema's minLength/maxLength, a minor wasted clause.

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?

Output schema exists so return values need no prose, and annotations cover the safety profile; the description still supplies the retry/duplicate risk and scope limits an agent needs. The remaining hole is the semantics of the `purpose` enum, which nothing documents.

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 0%, so the description must carry parameter meaning. It restates constraints already enforced structurally (name 1-20 characters, purpose required) but never explains what `purpose` affects, whether it is user-visible, or whether it can be changed later. Useful reinforcement, but not compensating for the coverage gap.

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 ("Create a new, empty calendar owned by you") plus the outcome ("return its ID"). The scope exclusions ("does not invite anyone or change existing calendars") make it unambiguous against siblings like create_event or get_calendar_members.

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?

Clear context for invocation and explicit negative scope (no invitations, no mutation of existing calendars), plus a concrete recovery path: check list_calendars before retrying after a timeout. It stops short of naming which sibling to use for follow-up steps such as adding members or events, so not a full when/when-not/alternatives mapping.

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