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

Annotations already declare readOnly/idempotent/openWorld=false, but the description goes well beyond them by disclosing the entitlement model in detail: unpaid lists return only the first 5 rows plus locked.count and locked.by_type, records name a subject and only the first 3 related names per section, and contact/decision-maker values are never returned. It also names the response fields (`entitlement`, `locked`) that report what was withheld. This is exactly the behavioral context an agent needs to interpret partial results.

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 access/entitlement sentences are front-loaded and genuinely informative, but the final sentence is promotional copy ('7 days free at https://...'), which does not help an agent invoke the tool. The description is also long relative to the actual parameter guidance provided.

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 usefully describes what a result contains (subject plus 3 related names per section, entitlement/locked fields, locked counts by type), which is real value. It still leaves half the parameters undocumented, but for a read-only search tool the behavioral picture is largely complete.

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 only 17% (6 params, only investor_dfx_id documented in the schema), so the description must compensate. It does define dated_only and the occurred/observed semantics behind the kinds filter, but since, within_days, and limit are left entirely unexplained in both the schema and the description.

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 states a specific resource and scope: 'Acquisitions, IPOs and listings of venture-backed companies' with the reporting investor. It maps cleanly onto the enum kinds (ACQUIRED, IPO, PUBLIC_LISTING, PORTFOLIO_EXITED) and distinguishes this from financing/investment search siblings. It doesn't explicitly name a contrasting sibling, so it stops short of a 5.

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 rather than stated: the description explains what 'occurred' vs 'observed' means and that 'dated_only keeps only exits with a transaction date', which hints at when to set that flag. But there is no explicit guidance on when to use this tool versus search_vc_investments or search_vc_financings, and no prerequisites or exclusions are given.

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