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

With no annotations, the description carries the full burden and does well: it declares 'Read only', explains the { routines, partial } envelope, and defines 'partial' as 'some agents weren't read' — a non-obvious degradation state an agent must handle. It also clarifies that 'on' is false when paused OR when the task is done, which prevents a misread of the state field. It does not cover ordering or empty results, keeping it short of a 5.

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?

Everything is front-loaded into a single sentence with the resource first and the read-only/alternative note last. The parenthetical glosses are justified because there is no output schema, though the run-on density makes it harder to scan than it needs to be.

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?

For a zero-param, no-output-schema, no-annotation tool, describing the return shape and the 'partial' flag is the essential missing piece, and it is supplied. Only minor gaps remain (ordering of results, behavior when the user has no routines).

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?

The tool takes zero parameters, so the baseline is 4. The description instead spends its space documenting the response fields, which is the relevant semantic detail for a no-arg call.

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 the resource ('The user's routines') and enumerates exactly what each entry contains (id, name, running agent, schedule, on/off state, last/next run, instruction start), so an agent knows precisely what this returns. It also draws a boundary against the create path ('create_routine proposes a new one'), separating read from write.

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 a clear read-only framing and names an alternative (create_routine) for the creation case, which is the main confusion risk. It does not address when to prefer this over sibling listing tools like list_agents or search_runs, so the routing guidance is clear but incomplete.

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