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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds only 'Paged.', which is genuinely useful context, but says nothing about how filters combine, sort defaults, or what a reminder record contains.

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?

Two short sentences, front-loaded with the action and resource, then the filter scope, then the paging note. Nothing is padded or repeated unnecessarily.

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?

The 15 parameters are fully documented in the schema and there is no output schema to explain, so the description's main job is scoping, which it does. It could still note that filters are combinable and how results are ordered by default.

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% across 15 parameters, so the schema already documents dates, paging, sorting, IDs and limits. The description only recaps the filter categories (client, status, invoice number, date range, text) without adding syntax or defaults, which is the baseline-3 case.

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 gives a specific verb and resource ('List payment reminders (Mahnungen)') and enumerates the filter dimensions, so the agent knows exactly what is returned. It never explicitly contrasts itself with the closest siblings (billomat_get_reminder for a single reminder, billomat_list_invoices for the underlying documents), so it stops short of a 5.

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?

Naming the available filters implies how the tool is used, but there is no statement of when to prefer it over billomat_get_reminder or billomat_list_invoices, and no note that filters combine. Usage must be inferred from the filter list alone.

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