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

Beyond the supplied annotations (openWorldHint=false, destructiveHint=true), the description discloses that the investor's signing link is emailed externally and that no tokens are returned to the caller, both of which materially affect follow-up behavior. It does not address permissions, idempotency, or what happens to prior envelopes, which is a gap for a destructive-hinted mutation.

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?

A single front-loaded sentence with the operation and its effects stated first, and the parenthetical sourcing detail placed inline. It is dense but every clause carries information; the nested parenthetical slightly hurts scannability.

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 return values need no explanation, and the description covers the core workflow and the notable 'no tokens returned' caveat. For a 10-parameter, multi-signer mutation, however, it omits provider selection, valuation cap handling, reminder scheduling, and how investor entries map to signingOrder.

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 only 30% across 10 parameters, so the description should compensate more than it does. It clarifies signer ordering (company order 1, investor order 2) and the investor email delivery, but leaves provider, valuationCap, reminderIntervalDays, safeAgreementId, founderEmail, and stateOfIncorporation entirely to 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 operation (CreateSafeEnvelope), the resource (a two-party SAFE signing envelope), and the two side effects (rendering the SAFE PDF, inserting ordered signers). It also distinguishes the source of data (cap-table-supplied, fetched via company.GetSafeAgreement), which differentiates it from the generic signature_create_envelope sibling.

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 a clear precondition for use: the caller must already have fetched the agreement via company.GetSafeAgreement, and this tool only handles SAFE envelopes rather than arbitrary documents. It stops short of explicitly naming an alternative (e.g. signature_create_envelope for non-SAFE envelopes) or stating when not to call it.

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