Remove segment members

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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds genuinely useful context beyond that: the segment must be STATIC, contacts are preserved, and there is a 500-email-per-call limit. It stops short of stating auth requirements or precisely what the return payload contains (only 'the result of the membership change').

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?

Front-loaded with bolded section headers (Purpose, Not for, Returns, Use when, Note) that make scanning easy, and every line carries content. The markdown header-heavy formatting is slightly heavier than the short content warrants, but there is no filler prose.

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 mutation tool with no output schema, it covers purpose, exclusions, primary use case, and the batch limit, and notes the static-segment constraint. Remaining gaps are the undefined 'subscribed'/'createMissing' params and auth requirements, but nothing that would lead an agent to call the wrong tool.

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 75%, so most parameter meaning is already structured data. The description restates the 500-email cap that the schema's maxItems already encodes but does not clarify the statically-undefined 'subscribed' or 'createMissing' parameters, which are unexplained in both places. Baseline 3 is appropriate when the schema does most of the work with no compensating detail added.

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 ('Remove contacts from a STATIC segment') and immediately clarifies scope ('The contacts themselves are not deleted'). It explicitly names the siblings it is not (plunk_delete_contact, plunk_unsubscribe_contact), so an agent can distinguish it from adjacent tools without opening a schema.

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 explicit when-not guidance via 'Not for: Deleting contacts... or unsubscribing them', naming the exact alternatives to use instead, and pairs it with a positive trigger ('Use when: Pruning a hand-curated audience'). This is a full when/when-not/alternative triad.

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