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

With no annotations provided, the description carries the burden of behavioral disclosure. The word 'Read' signals a non-mutating operation, and the description explains what kind of result is returned ('the slots where the most people are free'). It does not detail edge cases like an event with no responses, but for a simple read tool this is adequate.

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?

Two sentences deliver the core purpose and the necessary parameter guidance with no filler. The description is front-loaded with what the tool does, and the id extraction hint is placed immediately after.

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 single-parameter read tool with no output schema, the description covers what is needed to invoke it correctly: the purpose, the result concept, and the source of the id. It could mention exact return formatting or empty-result behavior, but these are minor gaps for such a simple operation.

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% and already explains the id as 'the event id from the event_url (the part after /e/)'. The prose description repeats this same guidance, adding no new semantic meaning beyond the schema, so the baseline of 3 is appropriate.

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 uses specific verbs ('Read', 'get') and identifies the resource ('responses for an Overlap event', 'best meeting times'). It clearly defines the tool's function and distinguishes it from the only sibling, create_event, which is a creation operation.

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 provides clear context for when the tool is used—reading current responses and computed best times—and even explains how to supply the required id from the event_url. It does not explicitly state when not to use it, but the sibling tool is a create operation, so no true alternative exists for this read task.

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