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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real value beyond that: the shape of each row (transcript, analysis, costs, recording links) and the operational caveat that recordings need separate authentication, which an agent cannot learn from the schema.

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 tight sentences, front-loaded with the core capability and followed by the payload/auth caveat; no filler. The phrasing 'Read call logs, summary statistics and pagination' is slightly elliptical (pagination is a mechanic, not something read), costing a point.

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?

With 13 optional params and no output schema, the description does the important work of describing row contents and the recording-auth caveat. It does not state default scope (are all calls in the account returned when no filters are given?) or whether summary statistics are always returned, which leaves a modest gap for a tool of this breadth.

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 92%, so all 13 filters are already documented with defaults (page 1, limit 200/1000, sort started_at) and the order enum. The description only gestures at pagination and adds no filter-combination or date-format semantics, which is the baseline-3 case.

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 call logs) plus what else comes back (summary statistics, pagination), so an agent can tell it is the bulk call-listing endpoint. It does not explicitly differentiate itself from neighbours like get_metrics or list_simulation_runs, and the mention of 'summary statistics' slightly blurs the boundary with get_metrics.

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?

The description never says when to use this tool versus alternatives, nor when not to (e.g. use get_metrics for aggregate reporting, or that filters can be freely combined). Usage has to be inferred from the parameter list alone.

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