beel_get_default_series

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

Annotations already cover read-only/idempotent/no-destructive, and the description adds real value on top: environment is resolved from request context with no input, the collection is a fixed closed catalogue with no pagination/page/limit, every response holds the whole set, and the downstream failure code tied to a missing default is named. The schema-level 403 behavior for unreachable/nonexistent companies is also spelled out.

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?

Front-loaded with the core report, then the two outcome bullets, then environment and catalogue constraints. The closing 'Read before calling' block is useful but slightly long for a no-argument read; still, every section maps to a distinct decision the caller must make.

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?

There is no output schema, yet the description fully specifies the response shape (one entry per DocumentType with `exists` and optional `series_id`) and that it is never paginated. Combined with the safety annotations and the fully documented single parameter, an agent has everything needed to call and interpret this correctly.

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?

Only one parameter exists and its schema description is at 100% coverage and unusually rich (UUID, context source, header plays no part, 403 semantics), so the schema carries the meaning. The description correctly notes the tool 'takes no input' but adds nothing beyond that, which is the expected baseline when the schema does the heavy lifting.

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 states a precise verb and resource: it reports, per DocumentType, whether a default invoice series exists and its underlying series_id. This is clearly separable from beel_list_series, beel_get_series, beel_set_default_series and beel_ensure_default_series, since it is a read-only, argument-free aggregate over document types rather than a per-series lookup or a mutation.

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?

It gives a concrete reason to call it (a missing default means a document type cannot be issued without an explicit series_id and automatic flows skip with `failure.payment.skip.missing_default_series`) and points to prerequisite reading (beel_rules_list, beel://guardrails/...). It stops short of explicitly naming an alternative sibling tool and the condition that would select it, so it is clear context without exclusions.

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