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

With no annotations, the description must carry behavioral burden and does: it discloses coverage caveats ('2003 reads low... offerings registered before 4 Nov 2002 are outside the ledger'), clarifies 'current period is to date,' and defines each series precisely. Remaining gap is return shape, but the caveats are meaningfully transparent.

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 with the core statement, but the body is a dense, parenthesis-heavy wall of definitions in a single block, making it harder to scan than a structured list would be.

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 no-output-schema, no-annotation tool with only two optional params, the description supplies series definitions and data-coverage caveats that an agent needs to interpret results. Only minor gaps remain (return structure, per-form guidance).

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 only 50%: the form enum values have no individual descriptions, and period's default is in the schema but its semantics are only implicit. The description does explain that specifying a form swaps out the six default series ('Instead of the six series'), which adds real meaning beyond the schema.

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 verb ('counts') and resource (filings per year/month since Nov 2002), and enumerates each series it returns. An agent knows exactly what data it produces, though it never explicitly contrasts itself with siblings like search_filings.

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 introductory clause implies this is a time-series aggregation tool, and 'since November 2002' scopes it, but there is no explicit when-to-use/when-not guidance or mention of the sibling tools as alternatives.

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