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

With no annotations, the description carries full burden; it does disclose 'Read-only' (a useful safety signal) and enumerates the returned fields (contact, status, outcome, duration, sentiment, summary, recording URL), which compensates somewhat for the absence of an output schema. However it omits pagination behavior, defaults, and any permission/scope caveats.

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 sentences with essentially no waste, each contributing useful content (return fields, read-only). It could front-load the action better, but size is appropriate for the tool.

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?

The field enumeration is helpful given there is no output schema, but with 4 params, no annotations, and a close sibling, the definition leaves gaps: no differentiation from list_phone_calls and no usage context. Adequate but incomplete.

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 75%: id, limit, and offset are already documented in the schema, and status is an enum. The description does not clarify the status filter or add syntax/format meaning beyond the schema, so the baseline 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 is a noun fragment ('Calls with contact, status...') rather than a verb+resource statement; it never says it *lists* phone calls scoped to a campaign. The name/title carry the actual purpose, and the description does not distinguish it from the sibling list_phone_calls.

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?

There is no when-to-use guidance, no exclusion criteria, and no mention of the obvious alternative list_phone_calls (general vs campaign-scoped) or how this relates to get_campaign_phone_stats. The agent must infer scope from the name alone.

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