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

Annotations already declare the safe read-only, non-destructive, closed-world profile, so the description's job is to add behavior beyond that. It does add a genuinely important trait: weeks are Monday-start (Monday..Sunday), which an agent could otherwise wrongly assume is Sunday-start. It omits timezone/UTC handling and the shape of the returned bounds, which keeps 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?

One sentence, no filler, with the key constraint (Monday..Sunday) and the input format front-loaded. Nothing redundant with the title.

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 small utility with annotations covering safety, the description is close to adequate, but with no output schema it should still indicate the return shape (e.g., a start/end pair) and timezone semantics. Those gaps are modest rather than severe.

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 0%, so the description must carry the parameter burden — and it does, specifying the date format (YYYY-MM-DD), which is the only real ambiguity for the single required parameter. It does not clarify whether the date is interpreted as UTC or local.

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?

It states a concrete computation (week bounds) over a specific input (the week containing a given date), which is enough to separate it from the report-generation siblings. It is not tautological — 'week_bounds' alone would not convey the Monday..Sunday convention or the date-based lookup.

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 description is purely definitional: it never says when to reach for this tool versus create_weekly_report, render_report_text, or report_templates, nor does it mention prerequisites or typical callers. Usage is only obliquely inferable from the semantics.

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