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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds value beyond that by disclosing the returned fields (filing type, report period, filing date, document URL), though it omits recency window, sort order, and pagination behavior.

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?

Three sentences, front-loaded with the resource and scope, then return shape, then the optional filter. The inline example is somewhat redundant with the schema examples but is compact and shows required _apiKey usage.

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?

No output schema exists, so the description correctly compensates by naming the returned fields. For a simple read tool this is nearly sufficient, though the meaning of 'recent' (lookback window) and how limit interacts with total results remain 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 description coverage is 100%, so all four parameters are already documented in the schema, and the description's filing-type list duplicates the schema's enum-like examples. Baseline 3 — the description adds little parameter meaning beyond structured data.

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?

Specific verb+resource: retrieves recent SEC/EDGAR filings for a ticker, with the enumerated form types (10-K, 10-Q, 8-K, 20-F, 6-K). It is clearly distinguishable from siblings like fd_insider_transactions, fd_institutional_holders, and company_facts, which cover different datasets.

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?

Usage is implied by the word 'recent' and the optional filing_type filter, but there is no explicit when-to-use guidance and no routing to alternatives (e.g., when to prefer company_facts or fd_insider_transactions instead). An agent can infer the context but must decide alone.

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