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

Annotations already establish read-only, idempotent, non-destructive behavior, so the description correctly spends its words elsewhere: the API chooses the lookback window and arbitrary A/B ranges cannot be requested, mention volume is not article counts, and publication timing must not be framed causally. That is substantive behavioral context an agent could not infer from the schema.

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 usage trigger followed by labeled Selection, Presentation, and Evidence blocks, so an agent can skim to what it needs. Sentences are dense but each carries distinct instruction; no filler. Slightly long for two parameters, but the content is non-redundant.

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?

An output schema exists, so return structure need not be described. Given that, the description covers the remaining gaps: when to invoke, what it cannot do (arbitrary ranges, exhaustive search), and how to present and evidence the results. Nothing an agent needs to call this correctly 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?

With 100% schema coverage the baseline is 3, and the description adds value on top: it tells the agent to use the resolved ticker identifier and an explicit anchor day, and reinforces that the anchor does not give control over the returned news range. That clarifies the intent behind both parameters rather than restating their types.

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 opening clause states the resource and scope clearly: what was reported about an asset around a given day, plus daily topic attention. It distinguishes itself from video-chapter and web-search siblings via explicit exclusions. It never clarifies its relationship to the close sibling research_show_news, which is the one comparison an agent most needs.

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?

Explicit 'Use this when...' trigger plus a 'Do not use for...' exclusion list naming video chapters and exhaustive web search. It also tells the agent to resolve the ticker first and use an explicit anchor date. The only gap is that it does not route the agent between this tool and research_show_news.

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