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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered externally. The description adds nothing beyond that: it does not mention pagination behavior (despite cursor parameter), default limits, or what status='all' implies. With annotations present the bar is lower, but this adds essentially no behavioral context.

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?

Very short, only one sentence, but the brevity comes at the cost of missing information rather than being efficiently front-loaded. It is not bloated, but it is under-specified.

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 not be explained. However, with four optional filter parameters and pagination via cursor, an agent needs at least a hint about filtering, result shape, and relationship to status/provider. None is provided, making the definition insufficient for correct invocation in a large tool set.

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 100%, so the schema itself documents limit, cursor, status, and provider. The description adds no parameter meaning or filter syntax beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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 'List your recent calls' restates the tool name (list_calls) and title (List calls) with only a vague modifier 'recent'. It does not clarify what a 'call' is (API call? phone call? model call?) in a context full of workflow and cost-related tools, and it gives no way to distinguish this tool from siblings.

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 usage guidance at all. There is no indication of when to use this tool versus alternatives, no mention of filtering behavior, and no reference to any sibling tool.

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