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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds value beyond that by enumerating the returned fields (id, name, instruction, cadence, delivery, enabled state, last-run outcome), which is the kind of context annotations can't convey.

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, zero waste. The resource definition and return fields come first, and the actionable usage instruction is placed at the end where it drives the next decision.

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 output schema, the description compensates by listing the fields each routine carries. For a single-optional-parameter read tool this is close to complete; the only minor gap is no mention of result ordering, pagination, or scale limits.

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% and the workspace parameter's default/override behavior is fully documented in the schema. The description adds nothing about the parameter, which is acceptable at this coverage level but not additive.

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 states a specific verb (List) and resource (the assistant's routines) and even defines the resource as 'scheduled natural-language instructions run by the assistant', which removes ambiguity for an agent that has never seen this domain. It doesn't explicitly contrast with routines_create/routines_update, but the read-only listing intent is unmistakable.

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?

It gives an explicit trigger: 'Check this before creating a routine so you don't duplicate one that already exists.' That is a concrete when-to-use that routes the agent correctly. There is no when-not guidance, but for a harmless list call the risk of misuse is low.

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