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

Annotations cover the safety profile (readOnlyHint, openWorldHint, destructiveHint), and the description goes well beyond them: EDGAR coverage windows by form family (15 from 1994, issuer 25 from mid-2001, 25-NSE from 2005 Q4), which fields are XML-populated vs metadata-level, and the 'pure-publisher posture' read-only guarantee.

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 front-loaded with the core purpose and the subsequent dense passages on coverage windows and field provenance earn their place for a 10-parameter tool. It is long and could be broken into clearer sections, but there is little redundant filler.

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 still explains the return surface (structured 25-NSE XML fields, 15-family records are metadata-level, follow filing_index_url for the document) and the historical coverage limits. An agent has everything needed to call and interpret the results correctly.

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 100%, so the baseline is 3, but the description adds real interpretive meaning: action='delisting' vs 'deregistration' is a faithful form-to-rule mapping, 25-NSE is filed by the exchange (exchange_name/exchange_cik set) while a bare 25 is issuer-filed, and rule_provision carries the cited provision verbatim.

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 first sentence names the specific resource (SEC delisting/deregistration filings) and distinguishes the Form 25 family from the Form 15 family, including the Rule 12d2-2 basis and the 15F foreign-issuer variant. An agent can tell exactly what this tool returns and how it differs from other SEC-filing siblings 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?

It enumerates concrete user intents ('was/is a company being delisted', 'which companies went dark recently', 'what securities did an exchange remove') and suggests pairing with tender offers/8-Ks/insider sales around an exit event. This is clear context, but it never names a competing tool as an explicit alternative nor states when not to use it.

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