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

Annotations already declare readOnlyHint and closed-world scope, so the burden is light; the description still adds real value by warning that output 'can be long for a contact who got many emails' and by disclosing the unusual depth of the payload (events nested per send). It does not mention any size cap, pagination, or redaction behavior.

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?

Two sentences, scope first and the size caveat second; the long enumeration is dense but each item earns its place by defining the export boundary. Minor awkwardness in 'a contact and its address' keeps it from top marks.

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 carries the return-shape burden and does enumerate the data categories returned, plus a size warning for large histories. It leaves the serialization format and any pagination/limit semantics unstated, which is the main remaining gap for an export 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 0% with one parameter, but contact_id is self-explanatory and the description only vaguely gestures at it ('everything held about a contact'). No format, ID source, or error behavior is added, so it neither compensates for the coverage gap nor misleads.

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 an aggregate export of a specific resource and enumerates exactly what is included (contact, enrollments, sends with events, replies, unsubscribes, bounces, complaints, blocks, consents), which makes it unmistakably distinct from get_contact, get_contact_activity, and list_contact_enrollments.

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?

Names a concrete selecting condition — 'for a subject-access request' — which tells the agent when this aggregate tool is appropriate rather than the narrower siblings. It stops short of explicitly naming those alternatives or stating when not to use it.

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