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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety bar is met; the description adds genuinely new behavior beyond them — an authentication requirement and the deliberate collapsing of 'missing' and 'other-wedding' into one not-found result, which prevents existence probing. It also enumerates derived outputs (overlapping event ids, matched dress-code guide entry) that the agent could not infer.

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, front-loaded with the return contract before the caveats, and no filler about the tool's importance. The first sentence is field-dense but each listed field is load-bearing since there is no output schema to fall back on.

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?

With no output schema, the description correctly takes on the burden of describing return values and does so thoroughly, including computed fields and the not-found semantics. The only residual gap is the multi-wedding/wedding_id selection behavior, which the schema covers but the description only gestures at with 'the selected wedding'.

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 100%, so both parameters are already documented, including the multi-wedding conditional for wedding_id. The description only restates the 'selected wedding' scoping in prose and adds no format or constraint detail beyond the schema — the baseline 3 for a fully documented 2-param schema.

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 ('Returns one identified event in the selected wedding') plus the exact payload fields, which cleanly separates it from list_my_events (plural listing) and get_my_wedding (the wedding itself). The singular 'one identified event' makes the cardinality explicit.

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?

Usage is implied rather than stated: the singular 'one identified event' signals fetch-by-id versus the list_my_events sibling, but neither the list nor update/remove siblings are named. The line about missing/other-wedding events implicitly tells the agent not to use this tool to probe for existence, which is useful but indirect.

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