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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds real behavioral context beyond that: the tool selects the cheapest plan, applies a 4% client-payment fee only to Base, and returns both monthly and yearly figures. It doesn't disclose rounding, currency, or whether prices are per-seat, but the core computation is explained.

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, front-loaded with the purpose, then the pricing rule, then the optional-parameter cue. Every clause carries information an agent needs; nothing is redundant.

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 correctly states the return contents (monthly and yearly cost for the cheapest plan), and the fee logic is fully covered. Minor gaps remain around the shape of the response (plan name, fee breakdown) and currency, though the schema notes USD.

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 baseline would be 3, but the description goes further: it explains why takes_payments matters (Base charges 4%, Pro/Business do not) and what monthly_client_payments actually changes in the result. That is meaning the schema's terse property descriptions do not convey.

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 ('Get the cheapest Superset plan') plus the scope ('for a coach with this many clients') and the returned values ('monthly and yearly cost'). No sibling tool in the list (compare_with, find_template, get_page, list_program_templates, request_coach_trial) overlaps with pricing calculation, so the agent can route unambiguously.

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 a concrete conditional instruction for the optional parameter ('Pass monthly_client_payments to count that fee') and explains the fee rule that drives plan choice. It does not state exclusions or contrast with alternatives, but no sibling is close enough to require that.

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