get_estimates

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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the equity-only failure mode and the shape of the payload (small tables keyed by period).

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?

Front-loaded with the core purpose, followed by two short sentences of return details and the equity constraint. No filler; slightly loose line-wrapping but every sentence earns its place.

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 one-parameter read tool with annotations and an output schema, the description covers purpose, payload contents, and the key error condition. Return-value formatting is left to the output schema, which is appropriate.

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 coverage is 100% and the single 'symbol' parameter is fully documented in the schema (ticker/ISIN formats, redirect to 'search' for company names). The description adds no parameter detail, so the 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?

States a specific verb and resource ('Get forward analyst estimates for a Yahoo symbol') and enumerates the returned content (earnings/revenue estimates, EPS trend and revisions, growth estimates). It is clearly distinct from get_quote/get_financials, though it never explicitly contrasts itself with the closest sibling, get_earnings.

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?

Gives a clear usage constraint: 'Equity-only: an ETF, fund or crypto symbol answers with an error that says so.' That is an explicit when-not condition. It stops short of naming an alternative tool (e.g. get_fund_data) for non-equity symbols.

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