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

Annotations already declare idempotentHint=true and destructiveHint=true, so safety is covered; the description usefully adds the authorization/consent requirements, the tier gate, and the exact-intent confirmation behavior, which an agent could not infer from annotations alone.

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?

Four sentences, front-loaded with the core action, followed by prerequisites and the mutation-safety instruction. Dense but every clause carries information; no filler.

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 gating preconditions and confirmation flow. The lingering gap is the unaddressed nested period format and the unexplained 'revision' reference relative to a state-mutating tool with destructiveHint=true.

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 0%, so the description carries the burden. It explains intent for idempotency_key and confirmation, but never clarifies project_id, the nested period format (schema has a regex pattern), or what the 'current revision' it references corresponds to — that revision field is not present in the schema, which muddies rather than clarifies.

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 ('Start a monthly reporting period') plus the added scope of a 'source-linked evidence snapshot'. An agent can identify the action cleanly, though it does not explicitly distinguish itself from sibling close-lifecycle tools like founder_ops.prepare_monthly_close or founder_close.next_period.

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?

Provides concrete preconditions: Startup or higher tier, both read and write consent, a stable idempotency key, and exact-intent confirmation. It also instructs reading current state before modifying an existing record. It stops short of naming an alternative sibling or an explicit when-not-to-use condition.

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