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

With no annotations, the description carries the full burden. It does add two useful behavioral facts: a no-hallucination constraint ('No invented values') and an explicit cost of $0.25 per call, which lets an agent weigh invocation. It omits reliability details such as handling of long or malformed documents, failure modes, and what gets returned when fields are absent.

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?

Three terse sentences, front-loaded with the core action, then the accuracy constraint, then the price. Nothing redundant or padded.

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, so the description is the only place the return shape could be described, yet it only says 'structured JSON' without naming the extracted fields. For an extraction tool that is the single most decision-relevant missing detail, alongside input size/format expectations.

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?

Single required parameter with 100% schema description coverage ('Invoice or receipt text'), so the schema already defines it fully. The description adds no meaning beyond that but has nothing left to clarify, matching the baseline for well-documented single-param tools.

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?

Declares a specific verb (extract) and resource (invoice or receipt fields) with a concrete output form (structured JSON). The document types named make it clearly distinct from siblings like fikra_summarise_contract or fikra_screen_cv, though it never explicitly contrasts with them.

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?

No statement of when to choose this over the sibling extraction/summary tools, no prerequisites, and no guidance on unsupported input (e.g. what happens if the text is not an invoice). Usage is only inferable from the named document types.

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