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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), but the description adds a real behavioral fact not in any structured field: diagnostics are private to the owner and cannot be reached via public visibility. It stops short of describing pagination behavior for cursor/limit, which matters for a multi-page read.

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 sentences, each earning its place, with the core purpose front-loaded before the access caveat.

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?

An output schema exists, so return values need no explanation, and the ownership rule is covered. However, for a paginated read with three required parameters at 0% schema description coverage, the absence of any cursor/limit guidance leaves a real gap for correct invocation.

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 carries the full burden, yet it only hints at call_id via 'owned call'. The cursor and limit parameters (including the '0'-based cursor pattern and 1000 max) are left entirely unexplained beyond raw schema constraints.

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 private diagnostic events') scoped to 'an owned call', which distinguishes it from generic reads like get_call. It does not explicitly name a sibling such as get_call or get_call_listener, so the differentiation is implied rather than stated.

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 only guidance is an access rule ('Public call visibility never grants access to diagnostics'), which tells the agent a precondition but not when to pick this over get_call or get_call_listener. No alternatives, no exclusions, no usage context are given.

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