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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the description need not restate those safety traits. It adds context by indicating that the tool covers ELCC document identities, class dimensions, metrics, and citations, but it does not disclose the return format, pagination, or the 'internal' access implication suggested by the title, leaving behavioral detail largely to the annotations.

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 a single sentence with no filler, front-loading the action ('Describe') and domain ('PJM ELCC'). Each phrase adds a distinct content category (identities, dimensions, metrics, citations), so every word earns its place.

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, parameterless describe tool, the description is mostly sufficient: it names the domain and the kinds of information described, and an output schema exists to provide structural detail. It does not expand 'ELCC' or explain why 'class dimensions' means, but given the low complexity and the presence of an output schema, the remaining gaps are not severe.

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 input schema has zero parameters, so there is no parameter-level meaning for the description to clarify; the empty properties object says everything. Per the rubric, a 0-parameter tool gets a baseline of 4 since parameter semantics are not applicable, and the description does not need to compensate.

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 names a specific domain (PJM ELCC) and a concrete action ('Describe'), and it lists four content areas: document identities, class dimensions, metrics, and citations. This distinguishes it from sibling describe tools by focusing on ELCC, but the terms like 'class dimensions' and 'document identities' are somewhat jargon-heavy and the title's explicit 'Class Ratings' is not reflected in the description, so it is clear but not maximally crisp.

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 gives no guidance on when to use this tool versus alternatives. There is no mention of the companion query_power_capacity_accreditation_pjm_v1 or any exclusions such as 'do not use for other PJM capacity datasets', so an agent must rely on the general 'describe' convention and tool name to infer usage.

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