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

readOnlyHint=true already declares the safety profile, so the description only needs to add context. It adds that related entities (item, reason, customer, status, log) come back with the return and names the underlying endpoint, but says nothing about error behavior for missing ids or pagination/expansion options.

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 tight sentences: the return shape comes first, then the id provenance and endpoint. Zero filler and nothing important is buried.

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 only two parameters and no output schema, the description's enumeration of returned fields does real work in conveying the response shape. A brief note on behavior for an invalid or unknown return_id is the only material omission.

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 both parameters are already documented, including the project_id default. The description reinforces return_id's provenance from channable_list_returns but adds no format or edge-case detail beyond the schema, which is the expected baseline.

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 ('One return') and enumerates the embedded payload ('item, reason, customer, status and log'), which distinguishes it from channable_list_returns at a glance. The explicit note that return_id is the id field from channable_list_returns further pins down the relationship to its sibling.

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?

The pointer to channable_list_returns as the source of return_id gives clear usage context: list first, then fetch one. It does not state exclusions (e.g., when to prefer the list endpoint or what happens with an unknown id), so it stops short of full when/when-not guidance.

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