beel_get_series

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds context about fiscal guardrails (how invoice numbers are formed and why they cannot be rewritten) and points to a resource for details. This is beyond annotations and provides useful behavioral context, but it does not describe return format, error handling, or other side effects. It adds some value but not a rich behavioral layer, consistent with a baseline of 3 given strong annotations.

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?

The description is concise and well-structured: it front-loads the core purpose, then provides the endpoint, then a critical warning with a resource link, and finally points to exhaustive documentation. Every sentence earns its place; there is no filler. It is neither too short nor overly verbose.

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 simple get-by-ID tool, the description is complete: it states what is returned, provides the endpoint, alerts to critical guardrails, and tells the agent where to find exhaustive rules (beel_docs_search). It does not have an output schema, but it lists the returned fields. No additional context (e.g., pagination, ordering) is needed for a single-resource fetch. The pointer to docs ensures any deeper questions are addressed.

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 coverage is 100%: both company_id and series_id have descriptions. The company_id description in the schema is notably detailed (explaining it is the only source of context and that unreachable NIFs return 403). The tool description itself does not add meaning beyond that, except implicitly tying company to NIF. Since the schema already documents parameters well, baseline 3 is appropriate.

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 clearly states that the tool returns one invoice series of a company, listing the specific fields returned (code, format, counter state, document type, default flag). It uses a specific verb ('Returns') and resource ('invoice series'), and the scope is unambiguous. It distinguishes from siblings like beel_list_series (which presumably lists many) and beel_get_default_series (which gets the default) by focusing on a single series by ID.

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 implies usage: it returns a single series, so an agent would infer to use it when fetching a specific series by ID. However, it does not explicitly state when to use it versus alternatives like beel_list_series or beel_get_default_series, nor does it mention any prerequisites or exclusions. This is implied usage rather than explicit guidance.

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