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

With no annotations, the description fully discloses behavioral traits: never deleted, grows indefinitely, months with <20 daily records excluded, no authentication required, rate limits (60 req/min), and 5-min cache. No contradictions.

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 concise with no wasted sentences. It front-loads purpose, then details returned fields, exclusions, and access constraints. Each sentence adds value.

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 no parameters and no output schema, the description completely covers what the tool returns (fields like avgScore, minScore, etc.), exclusions (months with <20 days), and operational details (auth, rate limit, cache). An agent can use it without ambiguity.

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 tool has 0 parameters and schema coverage is 100%, so the description does not need to add parameter meaning. Baseline 4 is appropriate as the schema fully covers the parameterless interface.

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 it returns the permanent monthly archive of the Fear & Greed index with one row per calendar month, aggregated from daily snapshots. It distinguishes from siblings by emphasizing permanence and monthly aggregation, unlike daily fear_greed or fear_greed_history.

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 provides usage context by mentioning it provides macro sentiment context across months/years and that daily snapshots are purged. However, it does not explicitly state when to use this tool vs alternatives like fear_greed or fear_greed_history.

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