beel_get_by_id

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

Annotations already declare readOnly=true, idempotent=true, and destructive=false. The description adds valuable behavioral context beyond annotations: the `company_id` is the only source of context (BeeL-Active-Company header is ignored), and the 403 response for both unreachable and non-existent NIFs to avoid existence disclosure. This is meaningful behavior disclosure that the annotations do not cover.

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 well-structured with a clear purpose statement, an exclusion note, an endpoint reference, and a guardrail section. It is a bit long but every section earns its place, and the key purpose is front-loaded. The use of bullets and pointers to docs keeps it focused.

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 read operation with one parameter, the description covers what is returned, what is not returned, how to get the missing data, and points to guardrails for context selection. It does not describe the exact response schema, but that is not required given no output schema and the low complexity. The description is comprehensive enough for an agent to call it 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?

The schema description coverage is 100% and the single parameter `company_id` is already fully explained in the schema: it is the NIF, it derives the owning account, and it details how it plays in context and error responses. The tool description adds no additional parameter semantics beyond referencing the guardrails. The baseline of 3 applies since 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 specific verb ('Returns') and resource ('company (NIF)') and enumerates the exact data returned: fiscal data, activation state in Test and Live, and VeriFactu registration state. It also explicitly excludes invoice series, distinguishing it from sibling get/list tools. This is a precise purpose with clear differentiation.

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 clearly states that invoice series are not part of this response and points to the correct endpoint for them (`GET /v1/companies/{company_id}/series`). It also references 'Fiscal guardrails' and directs users to `beel_docs_search` for exhaustive rules. While it doesn't explicitly name an alternative tool, the endpoint reference and exclusion are sufficient for most usage routing.

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