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

"Read-only — never modifies data" merely restates the annotations (readOnlyHint=true, destructiveHint=false), so it adds no value beyond structured data. The only new info is tenant scoping, and there is no mention of pagination or ordering. With annotations already covering the safety profile, a 3 fits.

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 with the scope front-loaded. The trailing "Read-only — never modifies data" is redundant against the annotations, slightly diluting an otherwise efficient definition.

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 fields an agent can expect (codes, commission groups, payment arrangements). That covers the main informational need for a single-parameter read tool, though defaults and result ordering remain unstated.

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 100% and the single is_active parameter is fully documented in the schema, including its true default. The description's phrase "which partners are active" loosely signals the filter but adds no syntax or behavioral detail beyond the schema, 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 (List) and resource (partners) plus scope (for this tenant and their commission groups). It distinguishes itself reasonably from get_partner_commission_summary by covering the full partner roster rather than a summary, but it never names that sibling explicitly.

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?

"Use this to answer questions about which partners are active, their codes, commission groups, and payment arrangements" gives clear usage context. However, it offers no when-not guidance and does not route the agent to get_partner_commission_summary, which is the obvious competing sibling.

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