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

Annotations already declare readOnlyHint=true, and the description is consistent with that while adding real context: the pillar-to-headline methodology is not published, out-of-coverage responses carry a data_status with a reason, and such calls are not charged against the plan's monthly analyses. That quota and failure-mode disclosure is exactly the kind of behavioral detail annotations cannot express; only the response payload detail beyond the app link is thin.

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?

Front-loaded with the core purpose, then progressive detail about methodology limits, edge-case responses, and billing behavior. The trailing 'Read-only.' duplicates the readOnlyHint annotation and is the only sentence that does not earn its place.

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?

There is no output schema, so the description has to describe the return shape, and it does: score, pillar breakdown with underlying values, data_status plus reason on misses, and an app link. For a one-parameter read tool this is nearly complete; only the ticker resolution expectation remains unstated.

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?

With a single parameter at 100% schema description coverage, the schema already defines ticker with an example, so the baseline is 3. The description adds nothing about ticker format, case sensitivity, or whether a lookup via resolve_company is expected first, so it does not exceed the schema.

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 verb and resource: retrieve Returnolio's score for one company, including the pillar breakdown and underlying values. It is clearly a single-company scoring read, though it never distinguishes itself from close siblings such as get_stock_score, get_valuation, or compare_companies, leaving the agent to guess which scoring tool to pick.

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?

It implies usage conditions by explaining what happens for companies outside coverage, not listed, or not yet scored, which helps the agent anticipate a valid-but-empty call. However, there is no explicit when-to-use or when-not-to-use guidance, and no named alternative for cases like comparing multiple companies or retrieving score history.

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