spectral_ndvi

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

No annotations exist, so the description must carry the burden. It explains the formula and output range (-1 to 1), but does not disclose any edge cases, validation behavior, or side effects. The schema already enforces input ranges, so the description is minimally adequate but lacks deeper behavioral context.

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 extremely concise with three short sentences covering the action, formula, range, and use case. It is front-loaded with the verb 'Calculate' and contains no unnecessary words.

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 two-parameter tool with no output schema or nested objects, the description provides all essential information: what it does, how it works (formula), output range, and typical application. No significant gaps remain.

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 description coverage is 100%, and the description adds value by referencing typical satellite band sources (Sentinel-2 Band 8, Landsat Band 5), which helps users select appropriate inputs. However, it does not add meaning beyond the schema's own descriptions.

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: calculate NDVI from NIR and Red bands. It provides the formula and explains the index's use for vegetation health assessment, distinguishing it from sibling tools like spectral_evi or spectral_ndwi.

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 includes context for when to use the tool ('assessing vegetation health, density, and agricultural monitoring'), but does not explicitly mention when not to use it or provide comparisons with similar indices. The guidance is clear enough for a straightforward calculation.

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