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

With no annotations, the description carries the full load and does disclose meaningful behaviour: it is an advisory listing (it says which letter to send, not that it sends one) and it explicitly flags the boundary case of invoices that fall outside the server's capability. It stops short of stating read-only status, side effects, or permission requirements.

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 dense sentence that front-loads the purpose and then lists four distinct output categories, with no filler. It is a long clause chain that could be split for scanability, but every clause carries information.

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 must describe what comes back, and it does so concretely across all four result categories while implicitly covering both inputs. It omits read-only/mutation status and result shape details, which is the remaining gap for a two-parameter report tool.

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 both parameters are optional and fully documented in the schema (including the 'see what Monday will need' example and the default). The description adds only the loose mapping of "what falls due in the next few days" to within_days, 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 enumerates exactly what the tool produces: today's escalation-crossing invoices, the letter recommended for each and its waiting time, upcoming due items, and fully-lettered invoices needing an out-of-server decision. That is far more specific than the title alone, though it never names a sibling (overdue_list, aging_summary) to draw the boundary.

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 implied by "The day's chase list" and by the note that exhausted cases "need a decision outside this server," which quietly tells the agent when this tool is not the answer. There is no explicit statement of when to prefer it over overdue_list or aging_summary, so the guidance remains inferential.

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