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

Annotations already cover read-only, idempotent, non-destructive and closed-world behavior, so the bar is lower; the description still adds meaningful trust context by flagging that entries are self-posted and NOT verified. It does not describe what a returned entry contains, but the honesty caveat is the valuable part.

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 short sentences, zero filler, with the data-quality caveat front-loaded before the filtering capability. Every clause carries information an agent needs.

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 two optional params, no required params, no output schema and full annotation coverage, the definition is workable. The remaining gap is the shape of a returned company entry, which the agent cannot infer from either schema or description.

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 enum values and default are already documented; baseline would be 3. The description adds semantic nuance by framing 'looking_for' as what a company *says* it wants, which tells the agent these are self-reported intents rather than verified needs.

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?

Specific verb ('List') plus a precisely scoped resource ('companies in the free partner directory'), with the source and verification status stated up front. It is unmistakably distinct from the contract/tender/site siblings, which cover entirely different resources.

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?

It implies when the filter is relevant ('Can filter by what a company says it is looking for') and warns that entries are unverified, but gives no explicit guidance on when to call this versus not calling it, and no prerequisites. Adequate context, no routing guidance — and there are no competing siblings to route to, which softens the gap.

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