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

Adds real behavior beyond the annotations: results carry per-item 'why recommended' explanations drawn only from actual matches, and calendar data must be reduced to free/busy with event details never sent. The privacy/conflict-skipping constraint is genuinely useful. Note the description reads as a read/ranking operation while annotations set readOnlyHint=false without the description explaining what state changes; this is under-explained rather than contradicted.

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 dense sentences, front-loaded with the core action and scope before the calendar-data caveat. Every clause carries information, though the sentences are long enough that a scannable breakdown would read better.

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 10-parameter tool with no output schema and no parameter descriptions, the definition covers the operationally critical parts (weekend window, ranking inputs, busy semantics) but leaves most parameters undocumented. An agent can call it with defaults, but cannot confidently use the geographic and date-scoping knobs.

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 0%, so the description carries the full burden, yet with 10 parameters it only clarifies the busy entries (free/busy only, never event details) and hints at location sourcing ('saved or given location'). limit, timezone, weekend_of format, radius_km, country_code and location_label get no meaning at all.

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?

Specific verb (rank) + resource (events) + scope (coming weekend, Friday–Sunday local dates, near a saved or given location), plus the signal sources used. It is clearly distinguishable from siblings like search_local_events or list_local_event_alerts.

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 tells the agent when this tool applies (weekend ranking) and gives a conditional rule for calendar data: pass busy intervals 'if the user allowed calendar access'. It stops short of naming alternatives such as search_local_events for non-weekend or explicit-query searches.

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