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

Annotations already declare this a safe, idempotent, closed-world read, so the description's job is lighter. It adds useful content context (news tone, best/worst coverage, explanation of why) but says nothing about what happens when end_day is omitted or how fresh the note is.

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 front-loaded sentence that states cadence, domain, and payload without filler. It could be marginally sharper about the default date, but nothing in it is wasted.

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 rich annotations, one optional parameter, and no output schema, the definition is nearly sufficient. The remaining gap is the default behavior of an omitted end_day, which matters because the only parameter is optional.

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% for the single optional end_day parameter (YYYY-MM-DD week end), so the schema carries the semantics. The description adds no meaning beyond that, such as what the default week is or whether partial weeks are accepted, 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?

The description names a specific resource (the Monday weekly note on FTSE 100 news tone) and its content (best and worst covered companies and why), which is far more informative than the title alone. It is clear what an agent gets back, though it never contrasts itself with siblings like get_ftse100_today or search_news.

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: 'Monday weekly note' signals a weekly recap rather than a daily or per-company lookup, which nudges an agent toward the daily siblings for other needs. There is no explicit when-to-use, when-not-to-use, or named alternative.

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