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

Annotations already declare readOnly, idempotent, and openWorldHint=false, so the safety profile is covered. The description adds the meaningful behavioral detail that results are scoped to the visitor's borough, but says nothing about result cap (max 10), pagination, or what a result contains.

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?

A single front-loaded sentence with no filler; the time-format detail is parenthetical and compact. Slightly informal ("What's on") but it earns its space.

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 four-parameter, zero-required read tool with annotations and no output schema, the description covers intent and time scope. It omits what happens when `area` and `limit` are omitted (implied default of the visitor's borough, but unstated) and gives no sense of the returned result set.

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 all four parameters are fully documented in the schema, including the `when` enumeration and the area examples. The description's parenthetical ("today, tomorrow, weekend, week, or yyyy-mm-dd") merely restates the `when` schema, so the baseline 3 applies.

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+resource ("what's on" = list events) and scopes it to the visitor's borough and a day. It's clear what the tool returns, but it never distinguishes itself from siblings like area_now or noticeboard_search, so an agent must infer the split.

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 only implied by "in the visitor's borough" and "on a day" – the agent can guess this is a visitor-oriented events lookup. There is no explicit when-to-use/when-not-to-use statement and no named alternative among the six siblings.

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