set_index_line

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

With no annotations, the description carries the full burden, and it does disclose meaningful behavior: the value persists on the record, the write cost is paid once per record, and empty lines are refused rather than stored. It does not mention overwrite behavior, error conditions, or permission requirements, so it is not fully transparent.

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 first sentence front-loads the core purpose, and each subsequent paragraph adds usable guidance: workflow, content strategy, and rejection behavior. It is longer than the typical tool description, but the extra length is mostly substantive rather than filler.

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?

The description is reasonably complete for a two-parameter write tool, covering what to write, how to format it, persistence, and empty-line rejection. But it leaves gaps that matter for correct invocation: what key represents, whether an existing line is overwritten, and what response or errors the agent should expect.

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 0%, so the description must compensate. It defines the line parameter very well: a conclusion-focused sentence around twenty words, with a counterexample about question-shaped lines. However, the key parameter is never explicitly defined as the record identifier, and there is no example showing how the two parameters relate.

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 action and resource: Write the index line for one record, and defines what that line is for. It also distinguishes itself from memory_index by calling itself the half a model can do and a library cannot, which helps separate it from the sibling tool.

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 clear workflow: read needs_line from memory_index, write what each record concluded, and store it here. It also tells the agent what style of line to write and explicitly warns against writing the question the record answers, which is practical selection guidance. It does not enumerate when not to use the tool beyond the related memory_index context.

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