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

Annotations already cover the safety profile (readOnly, idempotent, closed-world), and the description still adds real behavior: amounts are never converted and totals are per-currency, inclusion thresholds (3+ rounds, 5+ rounds, 2+ rounds), always returns available_months, and the date_published/date_modified fallback chain. Only the return format/pagination is left implicit.

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 purpose before the long parenthetical inventory, and every sentence carries information. The report-contents enumeration is dense but earns its place; the definition is longer than typical without much true redundancy.

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 zero-required-parameter, read-only tool with no output schema, the description fully covers what is returned (report contents plus available_months and publication/modification dates) and the one behavioral rule an agent could get wrong (no currency conversion). Nothing needed to call it correctly is missing.

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 100% and the schema already says 'Omit for the latest', so the description's 'omit for the latest published edition' largely restates it. The only marginal additions are the strictness note ('unknown arguments are rejected'); baseline 3 applies since the schema carries the parameter semantics.

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+resource: a stored monthly report of Fintech Signals figures, with an enumerated content list (headline rounds, per-currency totals/medians, largest rounds, investors, debt/fund/IPO items). This clearly separates it from narrower siblings like largest_rounds or funding_summary, though it never names those siblings or states the boundary explicitly.

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?

Gives clear usage for the one parameter ('omit for the latest published edition') and warns that unknown arguments are rejected, but offers no guidance on when to pick this bundled report versus calling the individual slice tools (largest_rounds, most_active_investors, funding_summary) that overlap its contents.

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