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

Annotations already declare readOnlyHint, idempotentHint and non-destructive, so the safety profile is covered; the description still adds real context beyond that by naming the credential requirement and the exact failure mode (403 until the workspace is claimed) plus the result ordering. It omits rate limits and response shape, so a 4 rather than a 5.

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?

Four short sentences, front-loaded with purpose and paging, then prerequisites. 'Read-only' duplicates the readOnlyHint annotation, a minor redundancy, but nothing else is wasted.

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 simple two-optional-param list tool with rich annotations and no output schema, the description covers ordering, paging, auth prerequisites and a specific error path. Only the returned fields are unexplained, which is a small gap given no output schema exists.

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 limit and offset are already fully documented in the schema. The description only restates 'page with limit and offset' and hints that offset is for the next page, adding no new syntax or default behavior. 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 and resource ('List the customers in your workspace') plus a defined ordering ('newest first'), which an agent can act on immediately. It does not explicitly differentiate itself from siblings like get_customer or list_contacts, so it stops short of a 5.

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?

Gives concrete invocation context: page with limit/offset, read-only, requires a Last Price credential, and requires a claimed workspace with a specific 403 refusal for sandbox self-registration keys. It never names an alternative tool (e.g., get_customer for a single record) or states when not to use it, which keeps it below a 5.

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