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

Beyond the annotations (readOnlyHint=false, openWorldHint=true, destructiveHint=false), the description discloses that it moves money, that confirmation is on by default and can be disabled per-tool, that it affects other people, and that a Cotlet API key with app access is required. This is meaningful behavioral context; it does not describe failure modes or idempotency.

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?

The first two sentences convey the same action ('ring up one package... and record the payment'), which is redundant. The remaining sentences (confirmation, cross-user impact, API key) are useful and front-loaded, but the duplication costs it.

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 money-moving mutation with no output schema, the description covers the essentials an agent needs: it is a write, it moves funds, confirmation defaults on, it affects other people, and an API key with app access is required. Return-value details are not needed since 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 description coverage is 100%, so all four parameters are already documented with their sources (find_client, list_packages, list_locations, signed-in location). The description adds one real constraint — payment_type must match a named payment type in the Register — but otherwise adds little beyond the schema. Baseline 3 is appropriate.

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 gives a specific verb and resource: "Ring up a package for a client in the Register and record the payment." An agent can tell this is the sale/checkout action distinct from listers like meevo_list_packages or meevo_book_appointment. It does not name an explicit alternative, and the second sentence largely restates the first.

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?

Provides concrete usage context: money moves so confirmation is expected, each call is confirmed by default and that can be switched off for this tool, and it reaches other people so the user should confirm before each call. It stops short of naming an alternative tool or when-not-to-use conditions.

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