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

Annotations already establish readOnly, non-destructive, closed-world behavior. The description adds one genuinely useful fact beyond them — contact fields are masked by default — but says nothing about pagination limits, cursor semantics, or what 'permitted' means.

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 short clauses, front-loaded with the core action, with no filler. Its brevity is a virtue here even though content is thin elsewhere.

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 9-parameter listing tool with no output schema and no parameter descriptions, the definition leaves too much unstated — filter semantics, pagination, and the condition under which contacts are unmasked all remain unknown.

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?

Nine parameters with 0% schema description coverage, and the description explains only the masking concept that hints at include_contact. It says nothing about workspace, since/until, limit bounds, cursor, funnel, source, or step.

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+resource ('Read leads') clearly, so an agent knows it's a list operation over leads. No sibling covers leads, so differentiation is implicit rather than stated, which keeps it below a 5.

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?

No indication of when to use this versus customers_search or subscriptions_list, and no prerequisites for obtaining contact data beyond a vague 'unless permitted'. The agent must infer that include_contact matters.

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