market_movers

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

Annotations already establish a safe read-only, idempotent profile, so the bar is lower; the description adds real behavioral value by explaining the `measured` gating field and clarifying that departed apps carry their last rank instead of a delta. This is genuine output-semantics context not covered by structured fields.

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 core comparison is front-loaded in the first sentence, and the second sentence adds necessary output semantics. It is slightly dense with backtick and em-dash asides but no filler.

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 5-param, no-output-schema tool the description usefully explains the comparison baseline and the `measured` field, but it leaves the sibling-overlap question unanswered and never fully defines fields like `measured` or delta shape, so it is adequate but incomplete.

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 the schema already documents days, kind, genre, limit, and country. The description's mention of 'N days ago' loosely maps to days but adds no syntax or format detail beyond the schema, so baseline 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?

It clearly describes the returned data (climbers, fallers, entrants, exits on one top chart vs. N days ago), so an agent knows the resource. However, it never names or contrasts its very close sibling get_chart_movers, leaving the agent unable to distinguish the two.

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 when-to-use guidance, no prerequisites, and no alternatives. With a near-identical sibling (get_chart_movers) present, the absence of routing guidance is a notable gap.

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