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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered. The description adds genuinely new context beyond annotations: the default window is the last 7 days, and 'each row quotes the filing or call' tells the agent the payload carries source excerpts. It doesn't mention pagination or result caps.

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 tightly packed sentences with zero filler; the temporal scope and default window are front-loaded right after the resource, and the event list follows. Each 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?

With no output schema, the one line about row content carries the return-value burden, and it does so briefly but adequately. Parameters are covered well enough for a single required enum plus an optional week; only pagination/ordering behavior is left unstated.

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 50% — only 'week' is documented in the schema — but the description compensates by spelling out the six event kinds that populate the enum and clarifying that 'guidance' means raised or cut. It also restates the week default semantics. Minor remaining gap is that the kind enum values are already fairly self-describing.

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 resource (companies with a given filing event in the last 7 days or an earlier ISO week) and enumerates the event categories, so an agent knows exactly what is returned. It is clearly distinct from siblings like get_company or search_companies, which resolve entities rather than surfaced events.

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 parenthetical '(or an earlier ISO week)' hints at when to supply a week versus taking the default 7-day window, but only names the default implicitly. There is no explicit statement of when to prefer this over search_companies or other siblings, and no exclusions or prerequisites.

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