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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds only that lead_data's additional fields are included, and says nothing about pagination behavior (offset/limit are required despite looking optional), record caps, or ordering — gaps that matter for a paginated listing tool.

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 short, front-loaded sentence with no filler. It is efficient but under-specified rather than padded; the phrase "all additional fields in lead_data" is the only informative clause and is itself ambiguous.

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?

Three required parameters, zero schema descriptions, no output schema, and nine similarly named list/lead siblings — this needs far more than one sentence. Nothing tells the agent what a valid list_id is or how the lead_data payload is shaped.

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% and the description mentions none of the three required parameters. It never explains that list_id selects the saved list or that offset/limit drive pagination, forcing the agent to reverse-engineer semantics from types, defaults and min/max alone.

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 verb+resource ("Read saved leads") is stated, but the tool's defining scope — that it returns the leads belonging to one specific list identified by list_id — is never said. With siblings like search_leads, get_search_results, preview_leads and list_lists, an agent cannot confidently pick this one from the description alone.

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 when-to-use statement, no exclusions, and no mention of the obvious alternatives (search_leads, preview_leads, get_search_results). The agent must infer the selection rule from the tool name.

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