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

Annotations already declare readOnly/idempotent/openWorld, but the description adds real behavioral value beyond them: cost of 1 credit only when results return, zero cost on empty results, a never-padded result list, US-only scope, and excluded filing categories. That is exactly the extra context an agent needs before spending credits.

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?

Dense and long, but every clause carries information: scope, exclusions, provenance fields, and billing rules are front-loaded. Only the free-trial URL and some prose flourishes could be trimmed without loss.

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 names the returned fields (record_url, why_now, fit, searched_feeds) and what their absence/short list means, so an agent knows exactly what a correct call yields. Nothing essential for invocation or interpretation is missing.

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, but the description goes further by enumerating the event kinds (funding filings, new C-level, IPO, activist 5%+, layoffs, crowdfunding, YC) that map onto the trigger_types enum values and explaining that unspecified types default to a fitted selection. It does not clarify the 30/90-day option, but adds meaningful enum semantics.

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: takes your website, learns what you sell, and searches recent filings for up to 10 companies with a reason to buy. This is clearly distinguishable from siblings like enrich_person or get_dossier, which are not prospecting tools.

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?

Explains the required input (your business website), the sourcing model, and constraints (US companies only, funds and real estate excluded, free trial link). It gives clear context for when the tool applies, though it never explicitly names a sibling tool to use instead for adjacent needs.

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