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

Annotations already declare readOnlyHint=false, destructiveHint=false and idempotentHint=true, so the safety profile is covered; the description still adds real value beyond them by disclosing the permission requirement (agency owner), the validity constraints on the terms, the discount side effect, and explicit scope exclusions (no charge, no payment setup). It stops short of saying what happens on re-acceptance or which errors surface when eligibility fails, which the idempotent hint only partially covers.

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 sentences, no filler: action first, prerequisites second, scope exclusions last. Every clause carries information an agent needs before calling the tool.

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?

An output schema exists, so return values need not be described, and the description covers the mutation's prerequisites, side effect, and side-effect boundaries. The only remaining gap is edge-case behavior (already-accepted terms, ineligible agency) which an agent might want spelled out given this is a write operation.

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 both parameters are documented in the schema, so the baseline of 3 applies. The description reinforces that termsId must be 'in effect' and partnerId is the agency workspace, but adds no format, lookup, or selection guidance beyond what the schema already states.

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?

The description uses a specific verb+resource ('Accepts published wholesale terms for the agency') and states the immediate consequence ('applies their discount'), which lets an agent distinguish it from sibling billing tools like agency_billing_publish_terms or agency_billing_set_plan. It does not name the sibling it pairs with, so the differentiation is inferential rather than explicit.

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?

Preconditions are spelled out clearly: agency-owner authorization, terms must be in effect, and terms must apply to this agency. The closing sentence ('It charges nothing and doesn't set up payment') implicitly routes agents away from the collection/plan siblings for money movement, but no alternative tool is named for the case where acceptance is not yet possible.

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