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

Annotations already declare read-only, idempotent, open-world, non-destructive, so the safety profile is covered. The description adds real context beyond that: per-call cost ($0.003), newest-first ordering, and the returned fields (publisher attribution, sentiment, event type, materiality where classified).

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?

A single dense sentence with the core purpose and cost front-loaded before the field inventory. Efficient, though the trailing clause listing return fields is slightly list-like and the parenthetical price interrupts the flow.

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 read-only tool with no output schema, the description covers what is returned, ordering, and cost. Minor gaps remain (no note on empty results or result caps beyond 'limit'), but nothing essential for 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 description coverage is 100%, so both parameters are already documented, including the symbol examples the description repeats. The description adds no meaning for 'limit' or pagination behavior, so 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 resource ('News for one symbol') with scope qualifiers (headlines plus SEC filing events tagged with the ticker) and gives concrete symbol examples. An agent immediately knows this retrieves per-ticker news, distinct from the market/decision/token siblings.

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 implied by 'for one symbol' and the price tag ($0.003) hints at a metered call worth weighing, but there is no explicit when-to-use, when-not-to-use, or alternative named. The single-symbol scoping is the only routing signal.

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