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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. Description adds real-time, 5-min intervals, and 'for today' context, which does not contradict annotations and enhances transparency.

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?

Two sentences cover all essential info: data source, content, use cases. No wasted words, front-loaded with key details.

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 read-only tool with one param, annotations, and no output schema, the description sufficiently describes the data (sources, granularity, time frame). Lacks explicit return structure (e.g., units, fields), but still mostly complete.

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?

Input schema covers 100% of parameters with a description for 'limit'. The description does not add extra parameter meaning beyond the schema, but schema is adequate. Baseline 3.

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?

Description clearly states it provides a breakdown of real-time renewable generation in CAISO, listing specific sources (solar, wind, etc.) and noting it is a subset of caiso_fuel_mix focused on zero-/low-carbon sources. This distinguishes it from siblings.

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?

Explicitly provides use cases ('California renewable share right now', 'duck curve today') and states it's a subset of caiso_fuel_mix, implying when to use the alternative. Strong guidance.

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