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

Annotations already declare readOnly, idempotent, non-destructive and non-open-world, so safety profile is covered. The description adds genuinely useful behavior beyond that: it enumerates what is returned and notes the linked page holds the full description and registration details, steering the agent toward the link for anything not in the response.

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 what the tool does and how to construct the id. The return-field enumeration is long but earns its place because there is no output schema; minor redundancy with the schema's id description is the only waste.

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 carries the return-value burden and does so concretely (date/time, venue, address, organizer, price, age range, summary, link). Only error/invalid-id behavior is unaddressed, which is a minor gap for a one-parameter read tool.

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 the single parameter is already fully documented in the schema. The description restates the same rule ('the text after /event/') without adding format, edge-case, or validation guidance beyond it, so 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 and resource ('Get the details of one event') and pins the scope to a single event identified by id, which separates it in spirit from the list/search sibling find_kids_events. It never names that sibling though, so the differentiation is inferred rather than asserted.

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: the id-derivation hint ('the last part of the event link') suggests this is called after obtaining an event link from a listing or find_kids_events. There is no explicit statement of when to call this versus find_kids_events, nor any prerequisite or exclusion.

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