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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds real behavioral context by enumerating what the record contains — capacity, attending/waiting counts, registration and late-cancel deadlines — and by mapping to the underlying GET /events/{id} endpoint.

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?

One sentence plus an endpoint reference, front-loaded with the verb and resource. Every clause earns its place by telling the agent what the returned record includes.

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 partially compensates by listing the notable returned fields, and the schema fully covers the inputs. It does not specify error behavior for an unknown id, which is a minor residual gap.

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 event_id, expand, and fields are all documented in the schema itself. The description adds nothing about expand/fields syntax, 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 ('Fetch') and resource ('one class or appointment by id'), and the phrase 'by id' immediately separates it from the sibling goteamup_list_events. The included resource detail (capacity, counts, deadlines) sharpens the purpose beyond a tautology.

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 by 'by id' — fetch one entity when you have its id rather than listing. However, no sibling alternative (e.g. goteamup_list_events) is named and no exclusions or prerequisites are given, so the agent must infer when this is preferred.

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