La Tierra desde DSCOVR

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: if no date is provided, it uses the most recent available images. This default behavior is not in the annotations and is useful for the agent.

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: the first states the core function and the second gives default behavior and usage context. Every word earns its place, with no redundancy 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?

For a tool with one optional parameter, no output schema, and strong annotations, the description is sufficient. It covers what the tool returns (images), the default date behavior, and when to choose it over siblings, leaving no critical gaps.

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 schema covers the single parameter 'fecha' fully with pattern and description, including the default behavior. The description duplicates this information without adding new semantics, so the baseline of 3 applies.

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 uses a specific verb 'Trae' (brings) and clearly identifies the resource: full images of Earth from the DSCOVR (EPIC) satellite. It also distinguishes itself from sibling tools by stating the usage context 'cuando pidan ver la Tierra desde el espacio o fotos EPIC,' which separates it from Mars photos, APOD, and asteroid tools.

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 provides an explicit when-to-use instruction: 'Úsala cuando pidan ver la Tierra desde el espacio o fotos EPIC.' This gives clear contextual guidance, though it does not explicitly mention when not to use it or name alternatives, so it stops short of a 5.

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