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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds what the computation produces – conversion price, which of cap/discount applies, shares issued, post-round ownership and pool top-up – which is real behavioral context beyond the annotations. It doesn't flag edge cases (no cap and no discount, or both provided) but is otherwise informative.

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 front-loaded sentences with zero filler, plus a single supplementary link. The core purpose and the sibling distinction come before the optional URL.

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 no output schema, the description carries the burden of telling the agent what comes back, and it does list the calculated result fields. It's slightly thin on tie-breaking rules (cap vs discount) and default-behavior edge cases, but covers what an agent needs to call the tool.

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%, with each parameter (including safe_type enum and discount_pct semantics) fully documented, so the baseline is 3. The description adds no parameter-level 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 verb and resource: converts a YC-style SAFE (post- or pre-money) in a priced equity round, and enumerates the outputs (conversion price, cap-vs-discount, shares issued, post-round ownership, option pool top-up). It also names the sibling convertible_note as the tool for a different instrument, so an agent can separate the two without opening schemas.

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?

Explicitly routes interest-accruing notes to convertible_note, which is a real alternative in the sibling list. The scope condition 'in a priced equity round' is stated. No explicit when-not beyond the note distinction, so it falls short of a full 5.

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