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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, and the description still adds substantive behavior: it reads from a canonical holdings-backed profile, applies a verified FX conversion, and explicitly reports incomplete coverage rather than fabricating amounts. That data-provenance and null-handling disclosure is exactly the kind of context annotations cannot convey.

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 sentences, front-loaded with the usage trigger, then scope/provenance, then the read-only boundary — good ordering with no filler. The trigger list is long, but each item plausibly helps routing and nothing is redundant.

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?

With an output schema present, return values need not be explained, and the annotations plus description together cover safety, scope, data source, FX handling, and incompleteness reporting. The only unaddressed element is the behavior of the portfolio_name argument, which keeps this just short of fully complete.

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?

The single optional 'portfolio_name' parameter has zero schema description coverage and is never mentioned in the description, so the agent is not told whether omitting it means the default/primary portfolio or how non-matching names are handled. The parameter is small and self-descriptive enough that this is a minor rather than crippling omission.

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 concrete resource — the holdings-backed dividend profile of the signed-in user's portfolio — and enumerates the facets it covers (projected annual income, yield, growth, payout coverage, safety, paying holdings). It does not explicitly distinguish itself from close siblings such as get_dividend_calendar or get_my_portfolio, so an agent must infer that boundary from the topic list.

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 opening 'Use this when the signed-in user asks about…' clause gives a clear set of triggering intents, and the closing sentence adds a negative boundary ('not a trade or a confirmed payout record') that steers write actions elsewhere. No sibling tool is named as the alternative for overlapping questions, which is the only gap.

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