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

Annotations already cover readOnly, idempotent, and non-destructive behavior. The description adds genuinely useful behavioral context: the tool aggregates multiple market metrics, returns a single composite score plus components and trend, and is scoped to one market rather than the full metric set. It does not discuss latency or data freshness, but for a read-only index tool this is sufficient.

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 definition and return value, then gives use cases, an example, and exclusions. It is somewhat dense but efficient. A small amount of redundancy exists ('Returns ONE composite health number' repeats the earlier 'Returns...'), and the example call is questionable, but the overall structure is strong.

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?

The description is largely complete for selection and alternative routing, and the presence of an output schema covers return-shape details. However, the invocation guidance is contradictory: the schema accepts no parameters while the description implies a market parameter, leaving an agent without a reliable way to target a specific market. That gap prevents the description from being fully complete.

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 defines zero properties, yet the description tells the agent to try 'get_intelligence_index market=northern-virginia', introducing a market argument that is not represented in the schema. This is misleading and could cause an agent to make an invalid invocation. It conveys that a market name is conceptually relevant, but the added semantics are not backed by 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?

Clearly defines a specific verb and resource: a real-time composite market health score (0-100). It distinguishes itself from siblings by explicitly saying it returns ONE composite health number and naming get_market_intel and rank_markets as alternatives, so an agent can disambiguate it from the large sibling set.

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?

Provides explicit use cases ('is this market healthy', 'how does Northern Virginia look overall right now') and explicit when-not-to-use guidance with named alternatives ('use get_market_intel', 'use rank_markets'). It even includes an example call. The main flaw is that the example references a parameter not present in the schema, but the when-to-use guidance itself is exemplary.

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