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

With no annotations, the description carries the full behavioral burden. It does disclose some useful traits, such as 'latest annual' data and a limit of up to 10 companies, but it omits whether the operation is read-only, authentication requirements beyond the vague 'PRO' label, rate limits, and return behavior.

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 definition is a single, front-loaded sentence with no wasted words. It conveys the tool's scope and main constraint efficiently.

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 simple two-parameter tool with no output schema, the description is adequate: it names the metrics being compared and the 10-company cap. It still leaves the company identifier format and authentication details unclear, which are important gaps 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?

Schema description coverage is 50%: access_token is documented in the schema, while companies has no schema description. The description partially compensates by saying 'up to 10 companies', but it does not explain the expected string format for each company, such as ticker versus company name.

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 uses a specific verb ('Compare') and lists concrete financial metrics, so the tool's purpose is immediately clear. It does not explicitly distinguish itself from the sibling tools history and key_financials, which keeps it from a 5.

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?

Usage is implied by 'Compare ... across up to 10 companies', suggesting this is the multi-company comparison tool. However, it never states when to use it instead of history or key_financials, nor does it give exclusions or prerequisites beyond 'PRO'.

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