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

readOnlyHint=true already covers the safety profile, and the description adds the concrete payload fields (names, mobile, custom fields, addedOn, unsubscribedOn, reason) plus the backing endpoint. However, it says nothing about pagination behavior despite pp/page params, nor about the 'last' cursor semantics.

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?

A compact single sentence plus a parenthetical field list and an endpoint reference. It is front-loaded with the resource and free of filler, though the telegraphic fragments read more like notes than 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?

With no output schema, the description compensates by enumerating the returned fields, and all six input parameters are fully documented in the schema. The only gap is pagination and cursor behavior, which is not addressed.

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 the schema already documents pp, page, from, to, group, and subaccount in detail. The description only echoes the date-range and group concepts with no added syntax or format guidance, so it does not exceed the baseline.

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 clearly states the resource ('Contacts that opted out') and enumerates the returned fields, so an agent knows this is a read/list operation on unsubscribed contacts. It does not explicitly name sibling alternatives like firetext_unsubscribe_contact, but the read-vs-write distinction is inferable.

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?

The description notes 'Optional date range and group API id' but frames these as parameters rather than situations. There is no statement of when to reach for this tool versus firetext_get_contact, firetext_subscribe_contact, or firetext_unsubscribe_contact.

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