filings_latest_preview

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

Annotations already declare readOnly, idempotent, openWorld, non-destructive, so the safety profile is covered. The description adds genuinely useful non-schema context: it is free, requires no key or payment, and is capped at 10 records — none of which the annotations convey.

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?

The opening sentence is immediately duplicated almost verbatim ('The 10 most recent filings across all form types (form, company, ticker, filed_at only) - Free.' followed by the same phrase), wasting space. The remaining example, exclusion and behavior lines are well front-loaded but the redundancy costs it.

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 description compensates by enumerating the returned fields (form, company, ticker, filed_at) and the 10-record cap, and it discloses the free/no-key terms. Complete enough to call correctly; only the result ordering/pagination edge is 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; it simply confirms the no-argument nature with an example path (/v1/latest-preview). Baseline 4 applies for a parameterless tool.

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 (10 most recent filings across all form types) plus the exact fields returned, and implicitly scopes it as a free preview versus the paid full endpoint. An agent can distinguish it from filings_search without opening the schema.

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?

Explicitly says when to use it ('when you want a free glimpse of the 10 most recent filings') and when not to ('Not for full structured data (use filings_search)'), naming the alternative sibling directly.

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