calendar_discover

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

Annotations already declare readOnlyHint/idempotentHint true and destructiveHint false, so the safety profile is covered. The description adds genuinely non-structured context: that the tool reveals otherwise-hidden operations and roughly how many ops/areas exist, telling the agent what comes back from the call.

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?

Purpose and the 'call first' instruction are front-loaded in one dense sentence. The op/area enumeration is long and ends in truncated fragments ('+2 more', '+1 areas'), which is mildly awkward but still communicates scope for a catalog tool.

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?

There is no output schema, so the description must convey what the tool yields; it does so at a high level (catalog plus hidden tool names). For a read-only, zero-required-parameter discovery tool this is close to sufficient, with only the exact response shape left implicit.

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 single 'query' parameter is fully documented in the schema (100% coverage) as a filter keyword, so the schema carries the load. The description adds no syntax, matching behavior, or filtering semantics beyond what the schema already states, which is the baseline case.

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?

Names a specific verb and resource ('Discover calendar') and immediately states the mechanism: it lists the catalog and reveals hidden tools. It also enumerates the underlying operations, which distinguishes it cleanly from the parallel gmail_discover, drive_discover, sheets_discover siblings without opening any schema.

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?

Gives explicit ordering guidance ('call first, then call the tool by name'), which is exactly the sequencing an agent needs for a discovery/meta tool. It does not state when not to use it or when a sibling discover tool would be preferable, so it stops short of full routing guidance.

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