project_triangle

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

Without annotations, the description carries full burden. It discloses key behaviors: fills only unobserved cells, nan for rows with no observation, returns a dict with disclaimer. However, it does not mention error handling (e.g., factor length mismatch) or side effects, but overall is transparent for a projection operation.

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 (a few sentences), uses clear section headers (Args, Returns), and front-loads the main purpose. Every sentence provides necessary information without repetition or fluff.

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?

Given the tool's complexity (projection using chain-ladder), the description covers inputs, constraints, output format, and a notable behavioral detail (nan for no-observation rows). It references an auxiliary tool for triangle format, which is acceptable. Minor gap: no explanation of the 'disclaimer' purpose.

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?

With 0% schema coverage, the description adds significant meaning: triangle is 'as in compute_chain_ladder' (context), selected_factors has a length constraint and description of 'one factor per development-period transition'. This goes beyond the schema's mere names and types, though the triangle format could be more explicit.

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 the tool's purpose: 'Fill the lower-right (unobserved) cells of a cumulative triangle using the supplied age-to-age factors.' It uses a specific verb ('Fill') and resource ('cells of a cumulative triangle'), and distinguishes itself from sibling tools like compute_chain_ladder by focusing on projection with precomputed factors.

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 when age-to-age factors are already supplied (e.g., from compute_chain_ladder) but does not explicitly state when to use this tool versus alternatives. It lacks 'when-to-use' or 'when-not-to-use' guidance, leaving the agent to infer context from the sibling set.

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