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

The annotations already establish readOnly=true, destructive=false, openWorld=true, so the safety profile is covered. The description adds genuinely useful context beyond them: the exact SEC fields returned and a concrete cost of 2 credits, which affects invocation decisions. It still omits how multi-parameter calls resolve or whether results are paged.

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?

Two sentences, front-loaded with purpose then return payload plus cost — nothing extraneous for an agent to wade through. Minor waste from repeating 'Company Lookup' twice in the opening clause.

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?

An output schema exists, so the description need not detail return values, and the credit cost is a nice addition. However, with zero required parameters and four independent optional filters, the description never explains call behavior when no filter is supplied or how filters interact — a material gap for correct invocation.

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% with examples on every parameter, so the schema carries parameter meaning fully. The description only restates the same four lookup modes at a high level and adds no format, matching, or precedence semantics beyond what the schema already documents — baseline 3 applies.

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?

A specific verb ('matches') plus resource ('SEC registration records') and an enumeration of accepted identifier types (tickers, CIK, names, SIC) make the purpose unmistakable. It does not explicitly differentiate itself from nearby siblings like TickerSymbols or SECFilings, which is the only gap.

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 enumeration of identifier types — an agent can infer it should pass one of ticker, CIK, name, or SIC. But there is no explicit guidance on which identifier to prefer, whether multiple can be combined, or what happens when the tool is called with no arguments (all four parameters are optional).

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