Compare Market Periods

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, providing a safety profile. The description adds value by stating 'Does not assert causation' and enumerating returned statistics (averages, min/max/median, load stats, deltas), which goes beyond the annotations' safety information.

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 three short, information-dense sentences with no redundant phrasing. It front-loads the primary action and then covers outputs and limitations, earning every word.

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 the tool's moderate complexity, presence of an output schema, and full annotation coverage, the description is sufficient. It communicates the comparison scope, requested metrics, and a key caveat (no causation), making it complete for an agent to understand and invoke correctly.

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% (the 'request' property has a description), but that description merely rephrases the tool's purpose and does not explain individual fields in depth. The tool description contributes timezone context ('America/Edmonton') but does not clarify period inclusivity or ordering, so the baseline of 3 is appropriate.

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 'Compares aggregate pool-price and load statistics between two America/Edmonton market periods,' specifying the verb, resource, and scope. This distinguishes it from siblings like get_pool_prices or get_market_snapshot, which focus on single-period or non-comparative data.

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 clear context for when to use the tool (when comparing two market periods) but does not explicitly mention alternatives or provide when-not-to-use guidance. Sibling tool names exist but are not referenced, so it lacks the explicit exclusion typical of a 5.

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