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

Goes well beyond the annotations (destructive/idempotent/write): it discloses patch semantics ('Only the fields you send change'), destructive null semantics for tax registrations and the sales playbook, the required credential scope, and the 403 failure mode for unclaimed sandbox workspaces. These are exactly the traits an agent cannot infer from the schema or hints.

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 tight sentences, front-loaded with scope, then semantics, then exclusion, then prerequisites. No filler, no restatement of the tool name, and each sentence carries information the agent needs.

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 15-parameter mutation with annotations but no output schema, the description covers patch behavior, null semantics, auth, and failure modes. The only gap is that it says nothing about what a successful call returns or whether the response reflects the full settings object.

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; the description earns an extra point by stating the partial-update rule that governs all 15 optional fields and by reiterating the null-clears/resets semantics for the nested fields where misunderstanding is costly. It stops short of adding format or value guidance beyond what the schema already carries.

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?

Names a specific verb and resource ('Change your workspace settings') and then enumerates exactly which settings it covers (company details, tax id, currency, payment terms, invoice prefix/footer, tax, tax registrations, sales playbook). The line 'Model keys are managed in the dashboard, never here' draws a hard scope boundary that an agent can act on without opening the schema.

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 strong preconditions (Last Price credential with workspace settings write scope; claimed workspace required, sandbox keys 403 until claimed) and an explicit exclusion (model keys). It does not explicitly point at get_workspace_settings for reading current values or distinguish itself from update_billing_settings, so the alternative routing is implied rather than stated.

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