get_iso_context

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description doesn't need to repeat those. It adds valuable behavioral context: sections are filled in priority order under a token budget, with token counts and citable URLs, and the response structure is explicitly described.

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 front-loaded with the main purpose and includes all necessary details in a single paragraph. It is comprehensive but slightly verbose; it could be trimmed without losing clarity. Still, it earns its sentences.

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 that there is no output schema, the description compensates by fully describing the return structure (sections with id,title,text,tokens,as_of,cite) and the token budgeting behavior. It also covers all parameters and distinguishes from siblings, making the tool fully usable without additional context.

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%, so baseline is 3. However, the description adds context beyond the schema: it lists valid ISO values, states that max_tokens has a default of 4000 and range 200-8000, and explains the priority-order filling behavior, which is not in the schema.

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 provides a 'WHOLE-grid briefing' and specifies the resource ('US ISO/RTO context pack'). It uses precise verbs ('get', 'drop straight into'), and distinguishes from siblings by listing similar tools not to use (get_grid_data, get_grid_intelligence, etc.).

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 explicitly says 'Use when an agent needs a WHOLE-grid briefing' and provides an example ('Brief me on ERCOT'). It also lists exclusions with specific alternative tools, making it clear when not to use this tool.

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