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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower, and the description still adds real behavior: the status taxonomy (confirmed by two registers, announced by one, revised, disputed), the fact that filing sentences are quoted, and the ambiguity refusal path. It does not mention permissions, rate limits, or coverage limits of the source registers, so it stops short of a 5.

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?

Two sentences, no filler, with the resource and scope front-loaded before the long enumeration of returned fields. The first sentence is a dense catalogue that runs long, but every clause carries information an agent would otherwise have to discover.

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?

An output schema exists, so the enumerated return fields are somewhat redundant, but the description remains complete: input forms, error behavior, and the fiscal-year scope are all stated, and annotations carry the safety profile. Nothing needed to call it correctly is missing, though the distinction from the sibling date-listing tool is never resolved.

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?

There is a single parameter with 100% schema description coverage, so the schema already documents that 'company' accepts a 12-character ISIN or a French/listed name. The description restates that and adds resolution semantics (ambiguity is refused with candidates), which is marginally useful but largely duplicative of 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?

The description names a specific resource and scope: the dividend per share for one Paris-listed company in the current fiscal year, and enumerates the payload (amount, status, nature, ex-date, payment date, filings, prior-year amounts). It is clear and concrete, but it never references the sibling list_french_dividend_dates, so an agent must infer the boundary between the single-company detail lookup and the date listing.

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 gives invocation guidance (pass an ISIN or a company name) and a failure mode (an ambiguous name is refused with the candidates), which implies usage. However, it offers no explicit when-to-use/when-not guidance or routing against the sibling tool, so the choice between the two remains inferred.

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