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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds that it returns specific fields (names, symbols, markets) and explicitly states it does not change the watchlist or holdings, which reinforces the non-mutating nature. This adds some value beyond annotations but isn't rich with additional behavioral details.

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 two short sentences that front-load the purpose and immediately state the return content and non-mutating behavior. There is no filler or redundant information.

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?

For a tool with no parameters and a full output schema (which describes the return structure), the description covers the purpose, the exact return fields, and the read-only nature. Nothing an agent needs to decide to call it 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?

The tool has zero parameters, so there is nothing for the description to explain. Per the calibration rule, a baseline of 4 applies when there are no parameters. The description doesn't need to add parameter 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?

The description clearly states the verb 'Read' and the resource 'companies followed by the authenticated user', and specifies what is returned (names, symbols, markets). It distinguishes itself from write tools like manage_watchlist and from other read tools like get_portfolio or get_peers.

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: it is for viewing the authenticated user's watchlist. It doesn't explicitly name alternatives or say when not to use it, but the read-only framing and sibling tool manage_watchlist make the intended use obvious. It's clear enough without exclusions.

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