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

The annotations already declare readOnlyHint=true and destructiveHint=false, and the description reinforces 'Read-only', which is consistent and adds little new information. The description does add the owner-granted access level context, which is useful beyond the schema, but does not discuss return format, pagination, or potential authorization nuances. Given the high annotation coverage, a 3 is appropriate as the description adds some value but is not exceptional.

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, information-dense sentence that front-loads the primary purpose, then adds the key access distinction and the portal designation. Every word earns its place, with no filler. This is appropriately concise and structured for maximum readability.

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?

Given that the tool has no parameters, a read-only annotation, no output schema in the context (though has output schema in real, but not provided here), the description is complete. It defines the resource scope (investor-linked companies), the caller type, and the portal context. An agent has all necessary information to decide whether to call this tool and can anticipate the result. Nothing is missing for correct invocation.

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?

The tool has zero parameters, and the schema description coverage is 100%, so there is nothing for the description to explain about parameters. The description adds context by clarifying the implicit scoping to 'linked investor stakeholder' companies, which enhances understanding of the result set. With no parameters, the description's main contribution is to clarify the implicit scope, which it does well, so a 4 is justified.

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 clearly states the verb ('returns'), the resource ('companies where the caller is a linked investor stakeholder'), and the distinction from a member. It also positions it as the entry point for the investor-facing portal, which is highly specific and differentiates it from other cap_table_get_* tools. This is a textbook example of a clear, unambiguous purpose.

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 explicitly labels this as the 'entry point for the investor-facing portal (B3)', giving strong contextual guidance on when to use it. It also clarifies the caller must be a 'linked investor stakeholder (not a member)', which is a form of usage constraint. However, it does not explicitly name sibling alternatives or state when NOT to use it, but the context is clear enough for an agent to infer the appropriate scenario.

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