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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior, so the safety profile is covered. The description adds valuable domain-specific context: the 'most can' score formula (coming=1, maybe=½), that only first names are shown, that friends who answered by link without an account are included, and that voting closes at 20:00 the evening before. It does not discuss error handling or permissions, but it meaningfully enriches behavioral understanding beyond annotations.

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?

The description is a single front-loaded sentence that clearly states the tool's scope before listing returned details. It is dense but contains no filler, though a run-on list structure reduces readability slightly compared with a more structured presentation.

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?

An output schema exists, so the description is not strictly required to explain return values, yet it does so thoroughly. However, it omits any parameter explanation and any usage guidance relative to alternatives, which leaves gaps for an agent deciding when and how to call the tool despite the simple one-parameter interface.

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 must compensate for the lack of parameter documentation. It does not mention planId at all, nor explain its format or source. The single required ID parameter is somewhat self-evident from its name, but the description provides no additional meaning.

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 title and description make clear this tool reads a single meetup/plan in full, listing the specific data it returns. It is not a tautology and is distinguishable from list_plans by virtue of returning one plan completely rather than a collection. However, it does not explicitly name a verb or contrast directly with sibling list_plans.

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 gives no explicit when-to-use guidance, prerequisites, or alternatives. It only states what one call returns, leaving the agent to infer that it should be used when details for a specific planId are needed. No exclusions or sibling comparisons are provided.

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