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

With no annotations, the description carries the full burden and does disclose genuinely useful traits: what each result contains ('a short analysis and key ratios'), that the underlying model is fundamentals-based, that the set is refreshed daily, and that it is a screen rather than personalized advice. It stops short of return shape, result count behavior, or any failure/limit semantics beyond the schema's 1-25 bound.

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?

Two compact sentences plus two short clauses, front-loaded with the core purpose. Every element earns its place: the selection criterion, the per-item content, the freshness note, the non-advice caveat, and the required citation URL.

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 read-only, single-optional-parameter tool with no output schema and no annotations, the description covers the essentials — what is screened, what each item holds, and update cadence. It could say more about the result set's shape/ordering, which the agent otherwise has to discover empirically, but nothing critical to correct invocation is missing.

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% for the single optional 'limit' parameter (range and default 10 are fully documented in the schema), so the baseline is 3. The description adds nothing about the parameter, but nothing is required of it either.

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 states a specific verb and resource ('Get ... screened undervalued stock ideas — stocks trading below modeled value on fundamentals') and defines the selection criterion, so an agent knows exactly what comes back. It implicitly separates itself from get_trending_stocks by content, but does not explicitly disambiguate from run_screener/list_screeners, which also return screened lists.

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 is only implied: the tool is for finding undervalued names, and 'A data-backed screen, not individualized advice' is a disclaimer rather than routing guidance. No alternative is named for the overlapping cases (run_screener for custom criteria, get_valuation_scorecard for a single name's valuation), leaving the agent to infer when this fixed screen is preferred.

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