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

Annotations only declare readOnlyHint=true; the description adds meaningful context beyond that: a paid key is required, paid keys are not yet available, and the output is an opinion rather than advice. These are genuine behavioral facts not present in structured fields.

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?

Three short sentences with the gating requirement ('Paid key required') front-loaded. Efficient, though the 'not a recommendation' and 'not on sale yet' clauses are somewhat tangential to invoking the tool.

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 one-parameter read tool with no output schema, the description covers the auth gate and the interpretive nature of the result. The main omission is any guidance on choosing this tool over sibling rating tools.

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 coverage is 100% and the single parameter is fully documented in the schema, so baseline 3 applies. The description adds no format or syntax detail beyond what the schema already provides.

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?

States a specific resource (the platform's own buy/hold/sell rating for a ticker) and the verb-equivalent ('get'), and clarifies it includes the reasoning behind it. It does not explicitly distinguish itself from siblings like get_composite or get_consensus, so it falls short of 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?

Provides a key prerequisite ('Paid key required') and frames the output's nature ('A judgement about the stock, not a recommendation'), which helps set expectations. However, it never says when to use this versus the many sibling rating/consensus tools, leaving selection to inference.

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