calendar_find_meeting_times

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds 'reads calendars and books nothing', 'Requires Calendars.Read.Shared', and details return behavior ('candidate slots with a confidence percentage and per-attendee availability'). This meaningfully extends the annotation metadata without contradicting it.

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 description is four sentences, front-loaded with the primary purpose, then covers return value, safety/next step, and required permission. Every sentence adds distinct value with no redundancy or fluff.

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 read-only tool with 7 well-documented parameters and no output schema, the description covers the essential context: what it does, what it returns, that it doesn't mutate, the required permission, and how to proceed with scheduling. It is sufficiently complete for an agent to select and invoke correctly.

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?

The input schema has 100% parameter coverage with detailed descriptions (e.g., 'Only suggest slots where at least this percentage of attendees are free'). The tool description does not add parameter semantics beyond what the schema already provides, so the baseline score of 3 applies.

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 clearly states the tool's function: 'suggest meeting times when the given attendees are free, ranked by how likely everyone is to attend.' It distinguishes itself from sibling calendar tools by emphasizing ranked candidate slots and that it 'books nothing', which sets it apart from calendar_get_event or calendar_get_free_busy.

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 use: finding meeting times based on attendee availability. It explicitly says it does not book and points to calendar_create_event for actual scheduling, giving an alternative action. It doesn't explicitly contrast with other read-only calendar tools like calendar_get_free_busy, so it stops short of a 5.

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