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

Annotations state readOnlyHint=true, and the description adds valuable behavioral context: 'Individual calendars are never exposed' and 'No auth needed — the meeting id is the capability.' This goes beyond annotations to explain privacy and access requirements.

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 concise (two sentences) and front-loads the core purpose. Every part adds value, with no extraneous words. However, some technical details (like the output structure) are packed densely, which could be clearer.

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?

The description explains the output structure well (counts, ranked slots, allFree) and notes auth requirements. However, given no output schema and 5 parameters, it lacks details on how parameters like 'tz' or 'durationMin' affect results, leaving gaps for an agent to apply the tool 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?

Schema coverage is only 40% (2 of 5 parameters described). The description only implicitly references 'meetingId' (as 'existing meeting') and does not explain 'to', 'from', 'tz', or 'durationMin'. With low coverage, the description fails to compensate, leaving significant parameter ambiguity.

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 returns 'aggregated group availability' for an existing meeting, specifying the output format (per-30-min-slot counts, ranked slots, allFree slots). It distinguishes from siblings like 'find_common_slots' and 'get_manual_availability' by emphasizing aggregation and privacy (individual calendars not exposed).

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?

No explicit when-to-use or when-not-to-use guidance is provided. The description mentions 'No auth needed' as a usage note, but fails to differentiate use cases from sibling tools like 'find_common_slots' or 'suggest_time'. Usage is implied but not clarified.

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