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

Annotations declare readOnlyHint=true and openWorldHint=true, so safety context is partly covered. The description adds genuinely useful operational detail those annotations cannot: the $0.002 USDC x402 cost per call and the fact that only the first matching slot is converted into an invite. It does not describe failure behavior (no common slot) or latency.

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?

A single sentence, front-loaded with the tool label and the core action, with cost appended at the end where it belongs. Dense but every clause carries information; slightly long to parse in one pass.

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 6-parameter tool with no output schema and only 33% schema coverage, the description gives a good behavioral picture but leaves most optional inputs (title, weekends, days, duration_minutes) unexplained. Adequate for understanding intent, thin for correct invocation.

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 33%, so the description must carry more of the burden than it does. It indirectly implies meaning for timezones, participants, and duration, but says nothing about the title, weekends, or days parameters. Baseline 3 with a partial gap is appropriate here.

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?

States a specific verb+resource: finds cross-timezone slots inside everyone's working hours over the next days, shows local times, and returns a .ics for the first slot. An agent knows exactly what it produces. It does not, however, differentiate itself from nearby siblings like meeting_room, schedule, or calendar_ics.

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 phrasing 'over the next days' and 'across time zones' implies the scheduling use case, so usage is inferable. But there is no explicit when-to-use vs when-not, and no mention of the likely alternatives (meeting_room for booking a physical room, calendar_ics for raw invite generation).

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