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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds the permission requirement ('Requires leads:read') and the default sort order, which is genuine extra context, but says nothing about pagination behavior or result shape.

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?

Three short sentences, scope and ordering front-loaded, then requirement, then filter usage. No filler sentences.

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 5-parameter, zero-coverage schema with no output schema, the description covers only two filters and omits page/search/status semantics. It is adequate to start but leaves meaningful gaps an agent would hit on real invocations.

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 0%, so the description must compensate and only partly does: it explains 'due' and 'newOnly' but leaves page, search and status undocumented in both schema and description. The status enum values (prospect/customer/archived/all) are never mentioned.

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 ('Read the owner's customer contacts for this website') plus a default ordering ('most recent enquiry first'). It does not explicitly distinguish itself from the sibling list_enquiries, and the phrase 'most recent enquiry first' could blur the boundary between contacts and enquiries.

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 concrete usage conditions: 'Set due to see contacts whose follow-up date has arrived, or newOnly for unread enquiries.' It also states the leads:read prerequisite. It does not name alternatives (e.g., list_enquiries) or say 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.