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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the 'read-only' restatement earns little. The added value is the account-scoping constraint ('customer must belong to the authenticated account context'), a genuine behavioral/authorization fact not present in annotations or schema.

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?

Three short, front-loaded sentences with no filler: purpose, one supported flag, then limitations. Efficient, though the endpoint path slightly duplicates what the name already conveys.

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 read-only single-resource getter with no output schema, the description covers purpose, endpoint, the one non-obvious flag, and the authorization scope. No output explanation is needed since no output schema exists, and no pagination concern applies.

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 71%, so the schema already documents base_url, api_token, account_id and the token aliases. The description only flags include_custom_fields (which is undocumented in the schema) and adds no syntax or format detail. Baseline 3 is appropriate.

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 ('Gets a specific customer') and anchors it to the endpoint /customers/:customer_id, which clearly distinguishes it from list_customers. It stops short of naming the sibling, but the singular-resource framing is unambiguous.

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 'Limitations' clause implies usage context (read-only, account-scoped), but it never states when to use this versus list_customers or get_account, nor any exclusion conditions. Usage is only implied.

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