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

The annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is fully covered. The description adds only the fact that results are paginated; it does not mention default page size, maximum limits, or result ordering, but with annotations carrying the burden that is an acceptable gap.

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 single sentence with no filler, and the essential scoping detail (contact list) is front-loaded before the pagination note.

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 simple read-only list endpoint with complete schema coverage and full annotations, the description supplies what an agent needs to select it and call it correctly. Only minor gaps remain around result ordering and what a page beyond the end returns, which are not essential.

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% – page defaults to 1, limit is constrained to 10-100 with a default of 20, and list_id is documented. The description adds no parameter semantics beyond that, so the baseline of 3 applies.

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 ('List contacts') plus the scoping qualifier ('in a specific MailerCloud contact list') and notes pagination support. It does not explicitly distinguish itself from close siblings like get_contact or list_contact_lists, so an agent must infer that this is the bulk-retrieval tool for members of one list.

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?

Usage is implied by the phrase 'in a specific MailerCloud contact list', which suggests the caller must already have a list_id, but there is no explicit when-to-use/when-not guidance or reference to alternate tools such as get_contact for a single record or batch_create_contacts for writes.

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