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

Annotations declare the safety profile (mutating, open-world, non-idempotent, non-destructive), and the description adds real context beyond them: the slug is shared with events so a collision is refused, and events order is preserved. It does not cover permissions or what the response looks like, but it meaningfully enriches the annotation baseline.

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?

Three dense sentences with the core action front-loaded and no redundant restatement of the name. Ordering constraints and the update path follow logically. Slightly clipped phrasing ("one an event holds is refused") costs a little clarity but keeps it compact.

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 mutating tool with no output schema, it covers the key call-time facts: slug collision behavior, event ordering, and the page-based update path. It still omits what headline means, whether title must be unique, and any permission requirements, so completeness is adequate but not full.

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 only 20%, so the description must compensate. It explains page (change an existing page), slug (shared namespace, refusals), and events (ordered id list), covering three of five params. title and headline remain undocumented in both schema and description, leaving a 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/update a booking page at /book/<slug>, describing it as a list of the workspace's events a person picks from. This is distinct from save_an_event, though the description doesn't explicitly name the sibling to differentiate.

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 distinguishes the two operating modes clearly with "Pass page to change an existing page" versus making a new one, which is genuinely useful. However, it offers no guidance on when to use this tool versus save_an_event, create_an_event, or publish_an_event, so alternative selection is left to inference.

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