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

Annotations already convey readOnly and openWorld hints. The description adds that the days_back parameter maps to specific windows (30d/60d/90d), providing useful behavioral context beyond 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?

Description is concise (two sentences plus argument list) and front-loaded. Every sentence adds value without redundancy.

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 simple two-parameter tool without output schema, the description covers purpose and parameter meaning adequately. The days_back mapping discrepancy slightly reduces completeness, but overall it is sufficient.

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?

Description adds meaning to both parameters: ticker as required symbol and days_back mapping to 30/60/90 days. However, the schema default is 14, creating inconsistency with the described mapping. This could mislead an agent.

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?

Description clearly states it retrieves analyst earnings estimate revisions (EPS upgrades/downgrades) over a lookback window. This distinguishes it from siblings like get_analyst_targets (target prices) and get_earnings_calendar (dates).

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 defines what the tool returns but does not explicitly specify when to use it over alternatives. However, the context provided (revisions) implicitly guides an agent away from related tools.

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