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

Annotations already mark the tool readOnly, and the description adds the incremental-change behavior: passing 'since' returns a list of what changed. It also clarifies that place_id is included for voted places, providing context beyond the schema.

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 sentences fully convey the tool's purpose, return contents, and optional parameter behavior. It is front-loaded with the core read action and has no filler or repetition.

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 simple read tool, the description covers what the call returns, how to identify the plan, and how the optional parameter works. With readOnlyHint already annotated and no output schema required, nothing essential is missing.

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 100%, so the baseline is 3, but the description adds meaning to the 'since' parameter by explaining that it takes a server_time from an earlier call and returns changes since then. This goes beyond the schema's brief ISO timestamp note.

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 uses a specific verb ('Read') and resource ('a plan'), and enumerates the key contents: title, event details, participants, availability, RSVP, best dates, and voted places with place_id. This clearly distinguishes it from sibling tools like get_checklist and get_expenses.

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 implies usage — read a plan when you need plan-level details — but does not explicitly state when to use this tool versus alternatives. It does provide one usage-related hint: passing 'since' can retrieve changes since an earlier call.

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