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

Annotations only say readOnly/idempotent/closed-world; the description adds substantial behavior: amounts are as announced in their own currency and never converted, size comes only from the latest first/interim/final close that has an amount, a target is never reported as size, results are sorted newest close first, and unknown arguments are rejected. These are exactly the data-semantics and error-behavior details an agent cannot get from the annotations or schema.

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 first sentence front-loads the payload and scope, followed by the currency and size rules and then the argument list. The trailing argument enumeration largely repeats the schema and could be trimmed, but no sentence is wasted or padded.

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?

There is no output schema, and the description compensates by naming the returned fields and the currency and size/target semantics; it also covers sort order, sector exclusions, and argument rejection. For a 7-parameter read-only search this is enough for an agent to call it 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 description coverage is 100%, so the baseline is 3, and the description mostly restates schema content (closed_after 'on or after this date' duplicates the schema wording, country slug example duplicates the schema's example). The one genuine addition is the 'q (or query)' alias, but that alias is not in the schema and contradicts 'additionalProperties: false' plus 'Unknown arguments are rejected', creating ambiguity rather than clarity.

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 description names a specific resource (venture funds) and enumerates what is returned: manager, status, stages, latest close, and size or target, plus explicit sector scoping (fintech, partly fintech, generalist). That is far more than a restatement of the name. It stops short of naming a sibling, so the boundary against list_fund_closes or get_investor_scorecard must be inferred from the field list.

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 scope is implied through the exclusion 'Funds focused on other sectors are not included' and through 'Newest close first' with a closed_after filter, which hints at close-driven browsing. There is no explicit when-to-use-this-versus-a-sibling statement anywhere, so an agent must infer that this is the broad search and list_fund_closes is something else.

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