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

readOnlyHint=true already declares the safety profile, and the description adds genuinely useful behavioral detail beyond that: the default sideloading of properties (addresses, phone, custom fields) and the specific aggregates returned. It stops short of noting error behavior for missing IDs.

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 dense sentences with the return payload front-loaded before the endpoint citation; every clause carries information and nothing is repeated from 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?

With no output schema, the description usefully enumerates the returned fields, and readOnly annotations cover safety. A little more on the sideload override or failure behavior would make it fully self-contained.

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 format of include. The description confirms the default sideload behavior, which adds marginal meaning, 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 customer), and enumerates the payload (order count, revenue, balance due), which distinguishes it cleanly from sibling booqable_list_customers. The endpoint reference pins the resource further.

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 the singular 'one customer' versus the list sibling, but there is no explicit when-to-use/when-not statement, no prerequisites, and no mention of alternatives such as list_customers for bulk retrieval.

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