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

Annotations already declare a safe read (readOnlyHint=true, destructiveHint=false), so the bar is lower; the description still adds real context by disclosing the paid API-key/credit requirement and the accepted LinkedIn slug patterns (/in/ vs /company/). It omits any note on precedence when both params are supplied or what an empty result looks like.

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 with zero filler; the capability is front-loaded and the operational caveats (URL patterns, paid key) follow in support.

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 two-optional-param lookup with no output schema and no required arguments, the description covers the essentials; the only real gap is what happens if neither or both identifiers are passed.

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, and the description earns above that by clarifying that LinkedIn inputs are typically /company/<slug> while /in/ profiles are also accepted, and that Twitter takes either a URL or a bare handle.

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 and resource ('Reverse-lookup an investor profile') and pins the input mechanism to LinkedIn or Twitter URL/handle, which distinguishes it from get_investor_by_domain and from search_investors without opening any 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?

Use is implied (you must already hold a social URL/handle), but the description never explicitly says when to choose this over get_investor_by_domain or search_investors, nor what to do when the URL is unknown.

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