cell_evidence

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

Annotations are absent, so the description carries the full burden of behavioral disclosure. It does add a useful behavioral detail: 'A cell whose evidence list is empty was filled from no quoted text,' which helps interpret the output. However, it does not explicitly state that the tool is read-only or describe any side effects, permissions, or failure modes. Given the read-like nature implied by 'Show,' a 3 is appropriate—some transparency is added, but not comprehensive.

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 two sentences, front-loaded with the core function and then the use case and an edge case. There is zero redundancy or filler. Every sentence earns its place, making it an exemplary model of conciseness.

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?

An output schema exists, so the description does not need to explain return values. The description covers the tool's purpose, a usage context, and a behavioral edge case (empty evidence list). The only notable omission is explicit guidance on when to prefer this tool over a sibling like cell_review, but the given context is otherwise sufficient for a simple two-parameter tool.

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 input schema provides 100% coverage for both parameters: 'column' is described as 'Exact column name' and 'unit_id' as 'The row, from table_read or units_assemble.' The description does not add any extra meaning to these parameters beyond what the schema already states. With full schema coverage, the baseline is 3, and the description does not elevate it.

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 opens with a specific verb-resource pair: 'Show a cell's value and the sentences it was drawn from, with document and offsets.' This clearly states what the tool does. It also distinguishes itself from siblings by framing the use case: 'This is how a reviewer checks a cell without opening the whole document,' which separates it from broader tools like matter_open or table_read.

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 provides a clear usage context: it is the way a reviewer checks a cell without opening the document. This implies when to use it, but it does not explicitly name alternative tools or state when not to use it. The sibling list includes cell_review, which might be a related alternative, but the description does not mention it or provide exclusion criteria, leaving a small gap.

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