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

Annotations already declare a non-read-only, non-destructive, open-world mutation, and the description adds a genuinely useful constraint: the list must contain every day id of the week, first to last — i.e. this is a wholesale reorder, not a partial move. It does not say what happens if ids are missing or foreign, but the core behavioral contract is disclosed.

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?

A single sentence with the ordering semantics front-loaded and the completeness constraint in parentheses; nothing is redundant or padded.

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 simple two-parameter mutation with full schema coverage, annotations, and no output schema, the description supplies what an agent needs to call it correctly. Only edge-case behavior (invalid or incomplete id lists) is left unstated.

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 coverage is 100% and both parameters already document their source (get_program) and that day_ids is 'in the new order.' The description's parenthetical reinforces the all-ids requirement but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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+resource (reorders the days of a program week) and specifies the ordering semantics. It is distinguishable from update_program_day and add_program_day, though it never names the closely related reorder_program_weeks sibling it mirrors.

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?

Usage is only implied: an agent can infer this is the tool for reordering rather than editing or adding days. There is no explicit statement of when to use it instead of update_program_day, or what prerequisite state (week must already contain the days) is required.

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