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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds genuine value beyond that: the behavioral note that a handle from before a rename still resolves, plus what the return payload contains. It stops short of covering error cases or rate limits, but for a read-only tool with annotations in place, the added context is meaningful.

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 short sentences, each earning its place: input definition with example, return value description, and the behavioral/workflow notes. It is front-loaded with the most important semantic information (the handle concept) and contains zero filler or restatement of schema details.

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 simple read-only tool with one fully documented parameter, the description covers the essential ground: input semantics, return contents, a backward-compatibility behavior, and the next workflow step. With no output schema, a slightly more explicit statement of the response shape or error handling for nonexistent handles would push it to 5, but the gaps are minor given the tool's simplicity.

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%, so the pattern and format of 'handle' are fully documented. The description adds the critical semantic layer the schema cannot: what a handle actually is in the domain (first path segment of a booking link) with a concrete example ('https://host/acme/demo' → 'acme'). This exceeds the baseline 3 by grounding the parameter in real-world usage.

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 title states a specific verb and resource ('List a person's or team's event types'), and the description reinforces it by naming the exact inputs (handle from a booking link) and outputs (person/team, event types with duration, price, hosts). It clearly differentiates from the sibling get_available_slots by positioning that tool as the follow-up step, making the boundary between the two obvious.

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?

The description gives concrete guidance on when to call it: when you have a handle, defined as the first path segment of a booking link, and it provides a clear next step ('call get_available_slots with one of the event type slugs'). It lacks explicit when-not-to-use conditions or an alternative-selection comparison against the other siblings, but the workflow guidance is strong enough to route an agent correctly.

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