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

Annotations already declare readOnly/openWorld/non-destructive, so the safety profile is covered. The description adds genuinely useful behavioral detail beyond them – 'cleaned' and 'head-only, capped' disclose that output is processed and truncated. It stops short of saying whether truncation is silent or how to retrieve the rest, which matters for a text-fetch tool.

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 tight sentence with no waste, and the most decision-relevant fact (it is a truncated excerpt, not the full document) is front-loaded.

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 carries some burden for describing the return value, and it does say it is cleaned, head-only, and capped. But it omits how to obtain content beyond the head/character cap and does not relate the cap to max_chars, leaving a gap for a fetch tool.

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 all four parameters are already documented, including the default-document behavior of 'document'. The description's 'primary document' phrasing merely echoes that schema note. Baseline 3 is appropriate when the schema does the heavy lifting.

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 and output form: cleaned text excerpt from a filing's primary document. An agent knows it fetches raw text content. However, it never contrasts itself with siblings like get_filing_documents or list_filings, so the reader must infer that this returns content rather than metadata.

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?

No when-to-use guidance, no prerequisites, and no alternative named. With many filing-adjacent siblings (get_filing_documents, list_filings, get_filing_amendments), the description does nothing to route the agent to the right one.

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