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

With no annotations, the description carries the full burden and does substantial work: it discloses return contents (local-timezone start times, venue, summary, tags, ticket/source links, match reasons), the geographic coverage limit and its failure mode (out-of-area returns not covered, no events), and that `from` overrides query time. It omits any auth, rate-limit, or latency behavior, keeping it short of a 5.

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?

Front-loaded with the verb and resource, and every subsequent sentence adds invocation or return-value information. The lengthy category enumeration and audience phrasing examples make it denser than strictly necessary, but nothing is filler.

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 9-parameter tool with a nested `near` object, no output schema, and no annotations, the description covers the essentials: what comes back, coverage boundaries, and pagination. Remaining gaps (sort semantics, category enum meaning, limit bounds) are minor because the schema already documents them.

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 already 89%, so the baseline is 3, but the description adds real meaning: `query` accepts natural language embedding time/place/audience, `from`/`to` override time in the query, and `offset` should be fed the returned next_offset. It does not clarify `sort`, `categories` enum values, or `limit` bounds beyond the 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 ('Find events happening in a city') and then enumerates the concrete domains covered (concerts, club nights, comedy, markets, festivals, classes), so an agent knows exactly what this retrieves. The coverage statement also implicitly separates it from the sibling list_coverage/get_event without needing to name them.

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 clear guidance on how to invoke: pass plain words in `query`, include who it is for in the same words, and use from/to/place/near 'when you already know them exactly'. Also explains the pagination path (re-call with next_offset). It stops short of naming alternative tools or explicit when-not-to-use conditions.

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