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

readOnlyHint=true already tells the agent this is a safe, non-mutating read, so the burden is lower. The description adds the endpoint and the expand hint but says nothing about error behavior for a missing id or what the returned object contains. Adequate but thin beyond the annotation.

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 short sentences, front-loaded with the core action and followed by the one actionable hint. No filler or repetition of the title.

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 single-resource read with no output schema, the description covers the identifier, the expand mechanism, and the backing endpoint well enough to call it correctly. It could mention that a nonexistent id returns an error, but nothing essential is missing.

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 100%, so the baseline is 3, and the description genuinely adds value by naming concrete expand values (usage_summary, next_billing_date, shared_with) that the schema only illustrates generically. It does not document the 'fields' parameter, so it stops short of a 5.

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?

The description states a specific verb and resource ('Fetch one customer membership by id') and even cites the underlying HTTP endpoint. The word 'one' plus the required id parameter cleanly distinguishes it from the sibling goteamup_list_customer_memberships.

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?

It tells the agent when to use specific expand values ('for usage, next bill and sharing'), which is useful, but never states when to use this tool versus the list variant or what happens when the id is unknown. Usage is implied by 'by id' rather than explicitly contrasted with alternatives.

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