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

Annotations already indicate readOnlyHint=false and idempotentHint=false, but the description adds no behavioral context beyond the output fields. It does not mention asynchronous execution, potential credit costs, or side effects, despite the presence of webhookUrl and forceRefresh parameters that imply such behavior. No contradiction with annotations, but the description fails to disclose meaningful behavioral traits.

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 description is a single, concise sentence that is front-loaded with the primary action and resource. It contains no redundant or filler content, and every clause adds relevant information about the tool's purpose and output.

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?

The description conveys the core function and key output fields (counterparty, deal status, value), but it omits important context such as whether the operation is asynchronous (hinted by webhookUrl) and the exact return structure. With no output schema, more detail about response format and behavior would improve completeness.

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%: domain, webhookUrl, and forceRefresh all have detailed descriptions in the schema. The tool description only mentions 'by domain' and does not add any new parameter semantics beyond what the schema already provides. Baseline 3 is appropriate.

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 'Research a company's recent M&A activity by domain' uses a specific verb and resource, explicitly identifies the input (domain), and enumerates the output facets (counterparty, deal status, value). This clearly distinguishes it from sibling signals tools such as signals-funding or signals-tech.

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?

The description provides clear context: use this tool to research M&A activity by domain. It does not explicitly name alternatives or exclusions, but the scope is well enough defined that an agent can infer when to use it. No guidance on when not to use it, so it falls short of a 5.

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