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

Annotations establish readOnlyHint=true and destructiveHint=false, and the description goes further by specifying that only selected values are returned, that the plan is never modified, and that a write tool must be invoked only after explicit confirmation. The host-capability fallback (no forms -> chat or open_planner) is behavioral context the annotations cannot convey.

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?

Three tight sentences: purpose first, then the read-only/confirmation constraint, then the fallback path. No filler, every clause carries operational information.

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 two-parameter read-only collector with no output schema, the description covers purpose, return semantics, mutation gating, and environment fallback. An agent has everything needed to decide when and how to call it, and no return-value documentation is required since there is no output schema.

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 0%, so the description carries the burden; it enumerates the five detail categories (availability, RSVP, place, expense, event) that map directly onto the action enum values, giving each choice concrete meaning. The 'plan' identifier parameter is left unexplained, so it does not fully compensate for the coverage gap.

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 and resource: it collects missing plan details (availability, RSVP, place, expense, event) via a native form. It explicitly distinguishes itself from the write siblings (set_availability, set_rsvp, add_place, add_expense, update_event) by declaring it returns values and never changes a plan.

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 when-to-use (missing availability/RSVP/place/expense/event details), when-not (never writes a plan), the follow-up condition (call the write tool only after explicit user confirmation), and a named alternative for hosts without forms (ask in chat or use open_planner).

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