DCPI Market Rank

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond the annotations: it includes a ~100-word narrative block, requires attribution to DC Hub under CC-BY-4.0, and lists the exact fields returned. This provides useful behavioral disclosure without contradicting 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 four dense sentences with no filler. It front-loads the core purpose, then adds the narrative/attribution detail, and finally gives concise usage and exclusion guidance. It is a bit long, but every clause earns its place given the tool's output complexity.

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?

With one parameter, 100% schema coverage, a rich output schema, and robust annotations, the description is complete for selection and invocation. It covers the purpose, output contents, licensing/attribution requirement, intended use case, and exclusions. There are no significant gaps for an agent to invoke this tool 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 schema already explains market_slug with examples and notes valid slugs come from rank_markets / get_market_dcpi_rank. The description only adds that it's for a single market, which is already implied by the tool name; it does not need to compensate for schema gaps. Baseline 3 is appropriate because the schema carries the parameter documentation burden.

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 opens with a precise declaration: 'DCPI rank for a single market' and enumerates exact outputs (BUILD/CAUTION/AVOID, composite_score, etc.). It explicitly distinguishes itself from sibling tools by saying this is 'ONE market in depth' and naming rank_markets and compare_isos as alternatives, so there is no ambiguity about scope.

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?

Usage guidance is explicit and actionable: 'Use to answer "should I build here?"' with structured reasoning and ready-to-cite prose. It also states clear exclusions: 'Do NOT use to rank many markets at once (use rank_markets) or to compare ISO grids (use compare_isos)', giving named alternatives and when-not-to-use conditions.

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