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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds genuinely new context beyond them: the result shape (time, venue, area, notes, citable link) and the UK-time nuance, which matter because there is no output schema. It does not disclose rate limits or result ordering, which is a minor remaining gap.

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 sentences, front-loaded with the core action and scope before the usage examples and the return-field note. The category enumeration in sentence one is long but does real work distinguishing the tool's coverage, so nothing is clearly wasted.

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 and no annotations covering return values, the description usefully compensates by describing the result fields and the citation link. Combined with a fully documented input schema, an agent has nearly everything needed to call and interpret the tool, missing only ordering/pagination expectations for the limit parameter.

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 area, date, type and limit are all fully documented in the schema itself (including the 4am 'tonight' rule and the seasonal-word behavior). The description adds query-phrasing examples but no parameter detail beyond what the schema already provides, 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?

Names the specific verb (list) and resource (regular nights out and one-off events) plus the scope (Manchester, UK, on a given date) and enumerates the covered event categories. This is far more specific than the title alone, though it never names or contrasts the overlapping siblings search_listings or seasonal_events, so an agent cannot tell from the description alone which one to prefer.

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 concrete user-question exemplars ("what's on tonight in Manchester", "comedy in the Northern Quarter on Saturday", "quiz in Didsbury tomorrow") that make the intended use case unambiguous. It stops short of stating when NOT to use it versus search_listings or seasonal_events, so there is no explicit exclusion or routing rule.

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