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

Goes well beyond the annotations: discloses that it affects orders and costs, that confirmation is on by default but toggleable, that it reaches other people (requiring per-call user confirmation), and that it needs an API key with app access. This is rich side-effect, safety, and auth context for a mutation tool.

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?

Purpose is front-loaded and readable, but the confirmation point is repeated twice almost verbatim ('so you confirm by default' / 'By default you confirm each call'), wasting space. The sentences earn their place individually but the redundancy 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 cost-affecting mutation with no output schema, the description covers the key concerns an agent needs: side effects on orders/costs, the confirmation requirement, inter-person impact, and auth. It is close to complete; it could note what a successful approval returns or irreversibility, but nothing critical is missing.

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 all three parameters are already documented in the schema. The description's note that a comment 'records why' roughly duplicates the schema's own comments description ('Why you approve for the client'), adding only marginal meaning. 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?

States a specific verb+resource (approve a choice/option of a selection) and a clear scope (on the client's behalf, when the client cannot approve). It distinguishes itself from read-oriented siblings like list_selections by naming it as the source of selection_id, so an agent can tell this is the write action that approves a selection option.

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 clear context for when to use it: approving on the client's behalf when the client cannot, mirroring how a builder would. It references list_selections as the source of IDs, but does not explicitly name any alternative tool or state when NOT to use it, so it stops short of full when/when-not guidance.

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