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

readOnlyHint=true already signals that this is a safe read operation, and openWorldHint=false supports the exhaustive 'all schedules' claim. The description adds that entries typically include rotation config and current on-call, which is useful. However, it does not clarify response format, ordering, pagination, or what 'typically' excludes, so the added behavioral detail is moderate.

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?

The description is two short sentences with no wasted words. The first sentence front-loads the scope, and the second adds the actionable detail about what each entry contains. It does not duplicate the title or the schema.

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 no parameters, no output schema, and read-only annotations, the description provides the key facts an agent needs: it returns all schedules, and entries carry rotation config and current on-call information. It is complete enough for safe tool selection, though a more precise entry shape would remove the slight ambiguity of 'typically.'

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?

There are zero parameters, so schema description coverage is vacuously 100% and there are no parameter semantics to clarify. The description correctly does not invent or repeat parameter information. This matches the baseline for a zero-parameter tool.

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 clearly indicates this tool returns all on-call schedules in the project and characterizes the entries, so it is not a tautology. The plural 'All' helps distinguish it from the singular sibling get_on_call_schedule, though that sibling is not explicitly named. A small gap is that the description does not itself state the verb 'list' or 'returns.'

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 usage guidance is implied: use this when you want all on-call schedules rather than a single one. There is no explicit statement of when to prefer get_on_call_schedule or any other alternative. The wording gives clear context but no exclusions or alternative routing.

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