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

Annotations declare readOnlyHint=true, so the safety profile is already covered. The description adds meaningful behavioral context: the comparison is based on investment cases rather than just ratios, and it will surface both supporting and challenging factors. There is no contradiction with annotations.

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 compact, front-loaded with the core purpose, and uses short clauses to cover use cases, exclusions, and argument guidance. Every sentence earns its place without unnecessary repetition.

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 there is no output schema, the description does a good job of explaining what the response will contain (valuation, investment case, supporting and challenging factors). It also covers usage triggers, exclusions, and a key parameter constraint. It is slightly incomplete on reading_level and other response modes, but generally sufficient for safe 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?

Schema description coverage is 0%, so the description must compensate. It does add useful meaning for 'entities' by stating the 2-5 range, and it hints at response_mode usage for beginners. However, it does not explain reading_level at all and only partially clarifies the response_mode enum, leaving a visible gap.

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 states a specific verb and resource: compare companies side by side, covering valuation, investment case, and supporting/challenging factors. It also distinguishes itself from sibling tools by explicitly saying 'Not for: one company → answer', so an agent can tell it apart from the answer tool.

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 gives explicit trigger examples ('X vs Y; which is the better buy; is X or Y more defensive'), a clear not-for case ('one company → answer'), and even mode advice ('response_mode=plain for beginners'). This tells the agent exactly when to invoke it and when to route to a sibling.

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